Sunday, May 01, 2016

The Desire for Sexual Identity--One of the "Very Widespread Regularities" of Human Nature

When I first began studying political philosophy in the late 1960s as an undergraduate student at the University of Dallas, it seemed to me that political philosophy was the study of human nature as universal human propensities diversely expressed in the variable historical circumstances of human individuals and human societies. 

In 1975, as a graduate student at the University of Chicago, I first saw Ed Wilson's Sociobiology on the new book table at the Seminary Coop Bookstore.  I remember thinking, as I skimmed over his last chapter on human sociobiology, that a Darwinian science of human nature could illuminate and adjudicate debates over human nature in the history of political philosophy.  In 1978, a conference paper by Roger Masters persuaded me that a science of evolved human nature could support a new understanding of Aristotelian natural right.  In the 1980s and early 1990s, I saw the writing about evolutionary psychology coming from Leda Cosmides, John Tooby, and others as contributing to this new science of human nature that could sustain what I called "Darwinian natural right."

Sometime around 1986, I met David Hull, a philosopher specializing in the philosophy of biology.  When I spoke to him about my interest in applying a biology of human nature to political philosophy, he warned me that evolutionary biology would not support any conception of human nature, if that was understood as some unchanging human essence.  Darwinian science denied such "essentialist" thinking, he explained, by showing that all living beings--including human beings--are historically contingent and variable, and therefore there is no enduring human nature and no enduring moral or political standard for judging human life rooted in human evolution.  Later, I discovered that one of my colleagues at Northern Illinois University--David Buller--had studied under Hull at Northwestern University, and that Buller's dissertation had elaborated Hull's argument against a biological human nature as assumed by evolutionary psychology.  In 2005, Buller's dissertation was published as a book--Adapting Minds: Evolutionary Psychology and the Persistent Quest for Human Nature

As the title indicates, Buller was responding to Cosmides and Tooby's edited volume--The Adapted Mind: Evolutionary Psychology and the Generation of Culture.  "The Adapted Mind" might suggest a single mind fixed by evolutionary adaptation for all human beings, which would constitute a universal human nature.  "Adapting Minds" suggests multiple minds that are changing in response to changing circumstances, which would mean that there is no enduring human nature produced by evolution.  Indeed, Buller declares his agreement with Michael Ghiselin's claim that "human nature is a superstition."

As I have indicated in a previous post, I agree with Buller that the evolutionary psychologists sometimes seem to stress the uniformity of human nature in such a way as to ignore the individual diversity that manifests the psychological polymorphism that has emerged from evolutionary history.  I also agree with him that in claiming that we all today have a "Stone Age mind" adapted to the environment of Pleistocene hunter-gatherers, the evolutionary psychologists can seem to mistakenly assume that there has been no human evolution over the past 10,000 years.

But on the most crucial point--the very idea of human nature--I am on the side of the evolutionary psychologists.  If one defines human nature in a silly way (as Buller and Hull do), then human nature does not exist.  But if one defines human nature in a sensible way, then human nature surely does exist.

Buller's silly definition of human nature is that it would have to consist only of traits that satisfy three conditions--first, they must be unique to human beings and thus not shared with any other animals; second, they must be invariably and exactly the same for all human individuals everywhere; and, third, they must be eternal essences that are not historically contingent.  It is easy for Buller to argue that human evolution has not produced a human species with such traits.

But a sensible definition of human nature does not require these conditions.  We can define human nature as constituted by that suite of generally recurrent anatomical, physiological, and psychological traits that characterize the human species.  Buller implicitly concedes this sensible definition of human nature when he speaks of human anatomy, human physiology, and human psychology as realities that can be scientifically studied.  Buller says that "psychology may one day provide us with descriptions of some very widespread regularities among the minds of our conspecifics" (456).  Well, then, if we define human nature as constituted by "very widespread regularities" among human beings in their minds and bodies, then human nature exists.

Among those "very widespread regularities," I include the twenty natural desires that constitute the motivational basis for moral and political psychology.  Because of the variability in those desires and in the circumstances of action across individuals and across societies, we need prudence or practical judgment in deciding what is best for particular individuals in particular circumstances.  But the regularity in the human nature of those desires sets some general standards for moral and political judgment.

Consider, for example, the natural desire for sexual identity.  Human beings generally desire to identify themselves as male or female. Sex is the single most important characteristic of personal identity.  It is the first question we ask about a newborn infant.  It is the first thing we notice about a person and the last thing we forget.  In all human societies, sex terminology is fundamentally dualistic.  Male and female are the basic sexes.  Others are either a combination of the basic sexes (hermaphrodites) or a crossover from one to the other (men who act as women or women who act as men).  All human societies have some sexual division of labor.  And although different societies assign somewhat different sex roles, thee are some recurrent differences that manifest a universal bipolarity in the pattern of human desires.  For instance, women in general (on average) tend to be more nurturing as manifested in a greater propensity to care for children, and men in general (on average) tend to be more aggressive as manifested in a greater propensity to violence.  Yet while these average differences are true for most men and women, for some individuals it is not: some women have manly desires, and some men have womanly desires.

Sanderson might say that I am confusing sex with gender.  Sex refers to the biological differences in anatomy and physiology between males and females.  Gender refers to the social roles of boys and men, on the one hand, and girls and women, on the other hand.  Moreover, Sanderson claims that while nonhuman animals show the sexual differences between male and female, only humans have gender.  And yet while Sanderson sees gender as different from sex, he does not see it as detached from sex.  Biological sex constrains but does not determine cultural gender.

The links between sex and gender are manifest in the universals of gender differences shaped by human evolution.  Sanderson surveys the evidence for at least six universals that we can identify as "very widespread regularities" of human nature.

(1) "Everywhere men display more aggressiveness."
(2) "Everywhere men are more competitive."
(3) "Everywhere men monopolize political leadership."
(4) "Everywhere women do the majority of the parenting."
(5) "Everywhere men and women display different kinds of cognitive skills."
(6) "Everywhere men and women have a strong sense of gender identity."

(1) Everywhere men on average are more aggressive than women, in the sense of a stronger propensity to physical violence.  As reviewed by John Archer and others, hundreds of studies using a wide variety of methodologies have shown in all societies greater aggressiveness on average for boys and men than for girls and women.

As is true for all six universals in gender, Sanderson (like me) stresses that the difference here is on average, which recognizes that some individuals depart from the average pattern.  Some women are more aggressive than some men.  Girls with above average levels of testosterone are more aggressive than girls with average levels of testosterone.  On average, most men have higher levels of testosterone than most women, but this is not true for all individuals.

The average gender difference in aggressiveness is connected through evolutionary adaptation to differences in bodily size and strength.  On average, men are taller, heavier, stronger, and more muscular than women.

Because of this difference in aggressiveness, war has always been an almost exclusively male activity.  The recent decision of the U.S. Department of Defense to open combat positions to women is a fascinating experiment.  Very aggressive women will be attracted to do this.  It is a safe prediction, however, that war will never be a predominantly female activity.

(2) Everywhere men are on average more competitive than women, in that men are more inclined to fight for high status and resources.  In every human society, there tends to be more men than women in the positions of highest status.  The best explanation for this is sexual selection: in evolutionary history, men have competed with other men for access to the resources necessary to attract high-quality mates, and women tend to prefer men with resources and high status.

(3) Everywhere the highest positions of political leadership are held predominantly by men.  Even in foraging bands, where there are no formal positions of political leadership, there is some informal leadership by men.  There is no clear evidence that any society has ever been a matriarchy, in which women hold all or most of the highest positions of leadership.

In modern industrial societies, the legislative, executive, and judicial branches of government are largely male dominated.  In recent decades, a growing number of women have entered the political realm.  The Scandinavian countries have an average of about 40 percent of the parliamentary seats filled by women.  As heads of state (presidents or prime ministers), men hold 95 percent or more of these positions around the world.

But, again, many individual women show high political ambition.  A Margaret Thatcher or a Hillary Clinton shows the ambition of high-testosterone women.

(4) Among many animals, males contribute little or no parental care for offspring.  Human fathers generally contribute more to parental care than is characteristic of over animals.  Even so, fathers on average contribute much less to parenting than do mothers.

This manifests the sexual division of labor in which women tend to engage in those activities that are compatible with extensive care for their children, while men on average have more freedom to enter roles that take them away from extensive parental care.

(5) There is plenty of evidence that all of the sex differences in motivation between men and women are connected to differences in their cognitive skills.  Mental testing shows that women on average are better than men in verbal ability, remembering the location of objects, and in reading facial expressions, while men on average are better in spatial ability, mental rotation of objects, maze running, and route finding.  These differences are magnified at puberty when testosterone levels increase in males.  These differences have been found among foraging bands and in some other mammalian animals.

There are two theories to explain the evolution of these sex differences in cognitive skills.  According to the sexual selection theory, males need good spatial skills to navigate large territories in searching for mates, which would be true especially for polygynous species, where males have larger navigational ranges than females.  According to the hunter-gatherer theory, the sex differences arise from the sexual division of labor, so that the cognitive skills necessary for hunting animals have evolved more prominently among males, and the cognitive skills necessary for gathering plants have evolved more prominently among females.  There is some evidence for both theories.

(6) In all human societies, men and women have a strong sense of their identity as male or female.  There is some evidence that this is correlated with differing prenatal levels of testosterone.  So that women who had high prenatal levels of testosterone during their development in the uterus are more masculine in their gender role identity.  Since men usually have had much higher levels of prenatal testosterone than women, this would partially explain why they generally have a more highly masculine identity in contrast to the more feminine identity of women.

All of this suggests that, as Sanderson says, "a completely degendered society is not possible" (225).  And thus we should expect that experiments in completely abolishing gender identity and creating androgynous societies will fail.

If sexual identity were a purely social construction, as many social scientists have assumed, then, as Sanderson indicates, we would have to make two kinds of predictions.  First, we would have to predict that the patterns of gender identity vary arbitrarily and randomly across societies, so that we would see the entire range of possible variation.  We might expect that in about one-third of societies, women would be more aggressively violent than men, and men would be the primary caregivers for infants and children.  In another one-third of societies, we might expect to see no sex differences at all in these traits, And, finally, in another one-third of societies, we would expect to see the pattern that is most familiar to us--men being more aggressive than women, and women being more inclined to child-care than are men.  But this prediction of totally arbitrary and random variation is not what we see.

The second prediction of the social construction theory is that those people who are born as genetic males could be successfully reared to have a female gender identity, and those who are born as genetic females could be successfully reared to have a male gender identity.  This experiment has been tried and failed.  The most famous case is that of the Canadian Bruce/Brenda/David Reimer.  This was the boy whose infant circumcision was so badly botched that he was castrated.  His parents were advised by John Money to remove the baby's testicles and rear him as a girl.  He predicted that socialization as a girl could turn Bruce into Brenda.  And for many years, psychology textbooks reported this as proof that gender identity was purely a social construction.  But Brenda never felt like a girl, and she was tormented by this.  When her parents finally revealed to her as a teenager what they had done, she insisted on turning herself back into a boy--David Reimer.  But David remained tormented by the effects of what he had suffered, and finally he committed suicide.

And yet, of course, gender identity is to some degree socially constructed, in that some patriarchal societies try to magnify the differences between the sexes in ways that allow men to totally dominate women, while other more egalitarian societies try to minimize the differences so that women have some freedom of opportunity to chose how they live, and to attain a social status equal to men.  In modern liberal societies, with gender equality of opportunity, there isn't much difference in the way  boys and girls are socialized, and as a result, sex differences are not a pronounced as they are in patriarchal societies. 

In such liberal societies, men and women are free to satisfy their natural desire for sexual identity and all their other natural desires in ways that conform to their individual propensities and abilities.  That's why liberal societies can be judged superior to illiberal societies, because liberal societies are more compatible with human nature.

Other posts on sexual identity and the debate over whether human nature includes more than two sexes can be found here, here, here, here, here, and here.

Tuesday, April 26, 2016

The Natural Desire for a Complete and Healthy Life

Human beings generally desire to live out a complete and healthy life.  Like other animals, they pass through a life cycle from birth to maturity to death.  Every human society is organized to manage the changing desires associated with this life cycle, which passes through distinctive stages such as infancy, juvenility, adolescence, adulthood, and old age.  Children, adults, and the old have different desires, and to satisfy these desires they must fill different roles in society. Although human beings will risk their lives for a good cause, they generally agree that to be fully happy one must live out one's natural life span.  To do this, they must strive to live healthy lives.  Much of the daily routine of life in every human society is devoted to satisfying the physical desires for bodily survival by eating, sleeping, and finding shelter.

There are at least four fundamental ways of making a living--foraging, farming, herding, and trading.  Foragers live by hunting and fishing for wild animals and gathering wild plants.  Farmers live by cultivating domesticated plants and herding domesticated animals.  The cultivation of plants ranges from horticulture (tending small gardens using simple hand tools) to agriculture (cultivating large fields with plows and draft animals).  In some areas that are too dry for cultivation, people can become predominantly herders or pastoralists.  Throughout human history, human beings have engaged in trading one thing for another; and some people have been specialists in trading.  Over the past 500 years, beginning in parts of Europe (such as the Italian city-states, the Dutch Republic, and England), trading has intensified in commercial societies that have become urbanized and industrialized, and most people live by buying and selling goods and services in markets.

Political philosophers from Aristotle to Adam Smith have recognized that how people make their living shapes the character of their social order.  Smith and other Scottish philosophers saw historical progress in the movement through the four fundamental ways of making a living, and they saw the emergence of modern commercial societies as bringing unprecedented growth in population, prosperity, and liberty, so that ever more people could satisfy not only their natural desire for a complete and healthy life but all their other natural desires.

Stephen Sanderson's Human Nature and the Evolution of Society is a survey of the evidence from evolutionary science that confirms the reality of those natural desires as constituting evolved human nature and of the evolutionary progress through the four ways of making a living.

As Sanderson indicates, the debates among anthropologists over how to characterize the life of human foragers have often been debates over political philosophy.  I would suggest that these debates began with the dispute between Hobbes, Locke, Rousseau, and Marx over the state of nature, because foraging bands are assumed to show evidence of how the earliest human ancestors lived and thus as showing original human nature.  Rousseau wanted to see that original condition as a state of perfect peace and equality.  Similarly, Marx wanted to see it as a state of communism.  The inequality of modern bourgeois or capitalist societies could then be considered a departure from that original condition.  By contrast, Hobbes and Locke saw human beings in the state of nature as hunter-gatherers living in small families but inclined to violent conflicts. 

It is generally agreed that among foragers, men are the hunters and women are the gatherers, so that there is a sexual division of labor.  Women do not usually hunt, because women do most of the child care, which is more compatible with gathering than hunting, and because men have the physical and mental skills that make them better hunters.

The importance of male hunting in providing animal protein has led some anthropologists to speak of early human evolution as the story of "man the hunter," which was the title of an important collection of papers on foraging bands published in 1968 and edited by Richard Lee and Irven DeVore.  Lee was a Marxist anthropologist who wanted to see foraging bands as completely egalitarian.  He also argued that most of the diet of foragers came from the food gathered by women rather than that hunted by men.  This allowed some feminist anthropologists to say that the story of human evolution was the story of "woman the gatherer," and that foragers should be identified as "gatherer-hunters."

In the 1970s, some anthropologists (such as Carol Ember) disputed this conclusion by pointing out that Lee's evidence was too limited.  Surveying 181 hunter-gatherer societies, Ember showed that the animal protein captured by both hunting and fishing provided over half of the calories for foraging people in most of these societies.  Then, in 2001, Lewis Binford's survey of over 339 foraging societies showed that while Ember was generally correct, she failed to see that the relative importance of animal and plant foods varied according to climate as indicated by the latitude of the location of a society.  Foragers living at lower latitudes (0-30 degrees) can easily find edible plants, and here gathering provides more than half of the diet.  But at higher latitudes (46-60 degrees), hunting and fishing provide over 90 percent of the diet.  This is an example of how the universal human nature of foraging varies in response to variable ecological circumstances.  To understand this, we need a human behavioral ecology that explains how variable human behaviors are adaptive responses to particular social and environmental contexts.

Lee's claim that foragers are completely egalitarian has also been disputed.  As I have indicated in previous posts (here), foraging societies do recognize informal leaders, although these leaders are checked by resistance to any arrogant dominance.  Moreover, male hunters are unequal in their hunting skills.  As Michael Gurven and Kim Hill (2009) have shown, hunting is such a difficult skill that some men never become successful hunters, and those men who are successful hunters have greater reproductive success, because women prefer skilled hunters, and men trade meat for sex.  This suggests that Rousseau and Marx were wrong to assume that the state of nature was a state of complete equality.

As I have indicated in a previous post (here), anthropologist Marshall Sahlins tried in the 1960s to defend Rousseau's account of the state of nature by arguing that foragers lived in the "original affluent society."  Like Rousseau, Sahlins claimed that although foragers were not affluent in the sense of being wealthy, they were affluent in the sense that their wants were so limited that they were easily satisfied with little effort, and therefore they were happier than people in wealthy societies whose artificial wants always exceeded their powers for satisfying them.  Sahlins saw evidence that foragers had to work only a few hours a week to provide for all their subsistence needs, far less than the forty hours of work for typical workers in the industrialized societies.  So it seemed that the foraging life was one of extensive leisure and little work. Anthropologists like Lee seemed to confirm Sahlins in pointing out that foragers like the !Kung in Southern Africa could easily feed themselves with Mongongo nuts and other edible plants that were abundantly available without any work required.

Although this foraging affluence thesis was accepted by many anthropologists, those who studied foraging societies had to admit that this idea was not well supported by the evidence.  As surveyed by David Kaplan (2000) and Robert Kelly (2013), the evidence shows that foragers have to work long and hard to secure their subsistence, and that they often live on the edge of starvation.  Sahlins and Lee had counted the hours devoted to foraging, but not the hours necessary for preparing and cooking food, for making and maintaining tools, and for building new huts when they move.  All of these activities require far more than forty hours a week.  And what Sahlins and Lee identify as hours of leisure are often hours of imposed idleness, as for example when !Kung must stay out of the midday heat of the African desert to avoid sunstroke and dehydration.  Foragers like the !Kung show high rates of infant and child mortality, short average life spans, and stunted growth from insufficient diets.  This hardly looks like affluence.

In overlooking this evidence of misery among foragers, and insisting that the foraging life is the happiest life for human beings, Sahlins and Lee were showing the bias of social scientists in the 1960s who wanted to criticize modern capitalist society by making the Rousseauian argument that the materialist consumerism, competitiveness, and inequality of capitalist life was depriving people of the happiness that their foraging ancestors had enjoyed.  Lee made this clear when he observed that anthropologists studying foraging societies are looking for alternatives to the "poverty, injustice, exploitation, war, and suffering" of human beings in the modern world:
"When anthropologists look at hunter-gatherers, they are seeking something else: a vision of human life and human possibilities without the pomp and glory, but also without the misery and inequity of state and class society. . . . I am convinced that hunter-gatherer studies, far from being the fantasy of uncritical romantics, have a role to play . . . as part of a larger movement to recapture wholeness from an increasingly fragmented and alienating modernity" (Lee 1992, p. 43).
The main Rousseauian idea for Sahlins and Lee is that while foragers don't have much, they don't want much, and they can easily satisfy their limited wants, while people in modern bourgeois societies have unlimited wants that they cannot ever satisfy, and thus they are miserable.  There is some evidence against this idea that foragers have limited wants, because anthropologists have noticed that foragers are often eager to have the goods that come from agrarian and Western societies: steel tools, shotguns and rifles, aluminum pots and pans, clothing from textile plants, motor boats, and all the conveniences of industrialized economies.  I have written about this in a previous post (here). 

Sanderson refers to this in concluding: "Virtually all nonindustrial populations have a great interest in modern technology" (49).  He seems to contradict this conclusion, however, when he says that foragers often prefer to live as foragers because it's an easier life, and "people have no inherent desire to advance their level of technology" (52, 58).

In any case, there is evidence that foragers understand how to plant and cultivate plants.  After all, some foragers are horticulturalists who tend gardens to supplement the food coming from hunting, fishing, and gathering.  So why did agricultural societies not begin to appear until about 11,000 to 5,000 years ago?  Part of the answer, Sanderson indicates, is that world climates were generally too cold, too dry, and too unstable prior to 11,500 years ago to make agriculture possible.  But while the climate change to a warmer, wetter, and more stable climate enabled agriculture, Sanderson suggests, population pressure caused it, because increasing populations would have forced people into cultivating crops to produce enough food to feed themselves.

Since about 3,700 years ago, some groups have relied on herding animals with little or no agriculture.  These pastoral societies have been common in parts of the world where there is too little water or warm weather to sustain agriculture--areas such as sub-Saharan Africa, the Arabian deserts, Central Eurasia, the Asian steppe, and Tibet.

Finally, the fourth fundamental way of organizing society for making a living--the modern commercial society--has become prominent only in the last 400 or 500 years and most prominent only in the last 200 years.  The fact that capitalism has apparently arisen only very recently in human social evolution might suggest that it's a purely cultural invention with no roots in human nature.  And, indeed, even proponents of the modern liberal social order like Friedrich Hayek have argued that market societies are contrary to the human nature that evolved in ancient foraging societies, and that the popular appeal of socialism can be explained as an atavistic yearning to return to the small foraging bands in which our prehistoric ancestors evolved.  Evolutionary psychologists like Leda Cosmides and John Tooby have embraced this idea in claiming that there is a "mismatch" between the human nature shaped by the Pleistocene environment of evolutionary adaptation and the human culture of modern commercial societies.

In various posts (here), I have argued against this.  Sanderson seems to agree with me.  Although he concedes that the "mismatch" theory is at least partially true, because some innate propensities that were adaptive in the ancient past might not be adaptive today, he is skeptical about whether it is totally true (7-8, 126, 143).  In particular, he suggests that capitalist social orders might satisfy the naturally evolved propensities for reciprocal exchange; and he cites Cosmides and Tooby as supporting this in a way that suggests that even they see capitalist social orders as satisfying some evolved propensities of human nature.

Adam Smith saw the opulence that results from exchange and specialization (the division of labor) as "the necessary, though very slow and gradual consequence of a certain propensity in human nature, which has in view no such extensive utility; the propensity to truck, barter, and exchange one thing for another." 

Since capitalism has arisen so recently in human history and in such special circumstances. it might seem implausible for Smith to suggest that it is rooted in the innate propensities of human nature.  But Sanderson suggests that we should understand this to mean that "capitalist relations lie dormant in human nature and develop when the preconditions appear" (68).  The propensity to reciprocal exchange--the natural human tendency to truck, barter, and exchange--has been manifest throughout all of human history.  There is some archaeological evidence for trading among ancient foragers hundreds of thousands of years ago.  Large trade networks began to appear thousands of years ago.  More recently, global trade networks have appeared with world commercialization.

To explain the evolutionary roots of this psychology of exchange, Sanderson quotes from Cosmides and Tooby's famous paper on "Cognitive Adaptations for Social Exchange," in which they presented their experimental studies of detecting cheaters (individuals who take a benefit without paying the cost) in Wason selection tasks.  They saw this as an adaptive psychology for social exchange that evolved among our ancient forager ancestors.  They thought this could be seen in studies of hunter-gatherer exchange:
"Despite the common characterization of hunter-gatherer life as an orgy of indiscriminate egalitarian cooperation and sharing--a kind of retro-utopia--the archaeological and ethnographic record shows that hunter-gatherers engaged in a number of different forms of social exchange (for an excellent review of hunter-gatherer economics, see Cashdan, 1989).  Communal sharing does not exhaust the full range of exchange in such societies.  Hunter-gatherers also engage in explicit contingent exchange--Fiske's 'market pricing'--in which tools and other durable goods are traded between bands, often in networks that extend over vast areas. A common form of trade is formal gift exchanges with carefully chosen partners from other bands.  For instance, aboriginal Australians traded tools such as sting ray spears and stone axes through gift exchanges with partners from neighboring bands.  These partnerships were linked in a chain that extended 620 km, from the coast, where sting ray spears were produced, to the interior, where there were quarries where the stone axes could be produced.  Here, environmental variation in the source of raw materials for tool making allowed gains from trade based on economic specialization, and the laws of supply and demand seemed to operate.  At the coast, where sting ray spears were common, it took more of them to buy an ax than in the interior, where spears were dear and axes cheap (Sharp, 1952).  Similarly, the !Kung of the Kalahari desert range engage in a system of delayed reciprocal gift giving called 'hxaro' (Weissner, 1982; Cashdan, 1989), through which they trade durable goods such as blankets and necklaces" (Cosmides and Tooby, 1992, pp. 216-17).
Here, then, Cosmides and Tooby seem to disagree with Hayek's claim that the modern extended order of liberal societies organized through trade requires a repression of the natural human psychology shaped by the evolution of social life in ancient foraging bands.  On the contrary, the modern liberal order can be seen as an expression of the evolved propensity for reciprocal exchange in modern conditions that allow for the extension of that propensity to embrace ever expanding social networks of trade.  This conclusion is reinforced by evidence of neuroendocrine mechanisms (such as oxytocin) that foster the trust that facilitate social exchange. (A post on this can be found here.)

A post on various explanations for the Industrial Revolution--including Deirdre McCloskey's appeal to the rhetoric of the "bourgeois virtues"--can be found here.

Tuesday, April 19, 2016

The Meaning and Purpose of Life in Twenty Natural Desires

To the question of the meaning and purpose of human life, the best answer--the answer we all give by the way we live our lives--is that we find the meaning and purpose of our lives in striving for the fullest satisfaction of our natural desires.  Evolutionary science helps to explain why we are moved by the twenty natural desires of our evolved human nature.  That scientific explanation is supported by lots of evidence.  One of the best general surveys of that evidence is Stephen Sanderson's Human Nature and the Evolution of Society (Westview Press, 2014).

Some of what Sanderson says, however, seems to deny that science can teach us anything about the meaning and purpose of life.  First of all, he warns against the naturalistic fallacy in inferring anything about moral values from natural facts.  And, secondly, he dismisses teleological thinking about the ultimate purpose of life as mistaken.  But implicit in Sanderson's writing is the recognition that we can rightly infer moral values from functional facts, and that even if we cannot find any cosmic purpose for life, we can find the immanent purpose of life inherent in our natural human desires.

After explaining the naturally evolved differences in the propensities and abilities of men and women, so that men on average are less inclined than are women to certain kinds of activities, Sanderson warns against the assumption that such natural tendencies tell us anything about what men and women should do.  This is the naturalistic fallacy:  deriving an "ought" from and "is."  One cannot infer a moral judgment from a purely descriptive statement about how human beings behave.  If men are naturally inclined towards careers such as firefighting, and women are naturally inclined towards careers such as nursing, it does not follow logically that men should be firefighters, or that women should be nurses (238).

And yet Sanderson seems to contradict himself in his writing about scientific research when he uses value-laden language--such as judging some behavior as "dysfunctional"--which seems to commit the naturalistic fallacy.  For example, when he reports Harry Harlow's famous experiments with young monkeys reared by artificial mothers made of wire rather than real mothers.  The monkeys exposed only to artificial mothers showed "severe emotional disturbance" and "dysfunctional" behavior, comparable to what happens to human children reared in orphanages without any maternal care (192-95, 210).

More generally, Sanderson concludes his book by arguing that evolutionary science can give an answer to the question of the meaning of life.  "The meaning of human existence is to achieve satisfaction with respect to the basic goals and desires that are part of human nature.  Since in real life these goals and desires are often in conflict, they must be harmonized or balanced in some way" (382).  He then offers a slightly modified version of my list of twenty natural desires.

And while Sanderson rejects any teleological belief in "some deep cosmic purpose embedded in the universe or, more likely, in the mind of God," he does see a purpose embedded in the desires of human nature: "If there is no ultimate purpose to our lives, life is emptied of all meaning.  Why then bother to live at all? The reason to bother is to fulfill the desires that emanate from our species-specific human nature.  This is sufficient.  There doesn't need to be anything else for life to be meaningful" (383, 386).

I agree.  Even if science cannot support a cosmic teleology of purposes set by a Cosmic God, Cosmic Nature, or Cosmic Reason, science can support an immanent teleology of purposes set by human nature, human culture, and human individuals, by which human nature and human culture constrain but do not determine the purposes set by human individuals in deciding how best to rank and harmonize their natural desires over a whole life well lived.

And so, for example, we can judge that children deprived of parental care are likely to show "dysfunctional" behavior because it is hard for children to become happy adults if their natural need for parental care has not been satisfied.

In this way, a natural science of human nature can support moral judgments through the hypothetical imperatives of given-if-then reasoning: given the evolved human nature of our desires, if we want to live desirable lives, then we must live in ways that are most likely to satisfy those desires.

Some of my posts on these points can be found here, here, here., here., and here.

Tuesday, April 12, 2016

Stephen Sanderson and the Twenty Natural Desires of Evolved Human Nature

If the good is the desirable, then human ethics is natural insofar as it satisfies natural human desires that naturally win social approval as useful or agreeable to oneself or to others.  The satisfaction of these natural desires constitutes a natural standard for judging social practice as either fulfilling or frustrating human nature, although prudence is required in judging what is best for particular people in particular social circumstances. 

By this standard, the modern bourgeois liberal regime can be recognized as the best regime so far in human history, because no other regime has satisfied those natural desires so well for so many people.  Or, to put it another way, the liberal regime has been more successful than any other regime so far in securing for human beings their equal liberty for the pursuit of happiness.

In Darwinian Natural Right and Darwinian Conservatism, I have argued that there are at least twenty natural desires: human beings generally desire (1) a complete life, (2) parental care, (3) sexual identify, (4) sexual mating, (5) familial bonding, (6) friendship, (7) social ranking, (8) justice as reciprocity, (9) political rule, (10) war, (11) health, (12) beauty, (13) property, (14) speech, (15) practical habituation, (16) practical reasoning, (17) practical arts, (18) aesthetic pleasure, (19) religious understanding, and (20) intellectual understanding.

I have argued that these twenty natural desires are universally found in all human societies, that they have evolved by natural selection over millions of years of human evolutionary history to become components of the species-specific nature of human beings, that they are rooted in the physiological mechanisms of the brain, that they direct and limit the social variability of human beings as adapted to diverse ecological circumstances, and that different individuals with different temperaments will rank these desires differently.

My selection of these twenty desires as natural and universal is supported by various kinds of evidence.  Social scientists who have surveyed the anthropological evidence have shown that there are hundreds of human universals, which are clustered around the twenty desires on my list.  Psychologists who study human motivation recognize these twenty desires as manifesting the basic motives for human action. Survey data from psychologists who ask people what is most important to them confirm the primacy of these twenty desires.  When Aristotle, in the Nicomachean Ethics and the Rhetoric, reviews the common opinions of human beings about what is desirable in life, he includes the twenty desires on my list.  When an Aristotelian scholar like Martha Nussbaum describes the "basic human functions" that support universal norms of moral judgment, she includes the desires on my list.

There is evidence that this pattern of twenty desires developed in the Pleistocene environment of our hunting-gathering ancestors, from about 1.6 million years ago up to the invention of agriculture about 11,000 years ago.  This was the evolutionary environment in which human nature was shaped by natural selection.  The historical record of human civilization since the development of agriculture shows human beings as moved by these twenty desires.

My survey of the evidence is not as good as that provided by Stephen Sanderson in two of his books--The Evolution of Human Sociality (Rowman and Littlefield, 2001) and Human Nature and the Evolution of Society (Westview Press, 2014).  Sanderson is one of the few sociologists who has promoted a Darwinian science of sociology.  Of all the social sciences, sociology has been most resistant to Darwinian science, because so many sociologists believe that human society is a purely cultural construction unconstrained by human nature.  Like me, Sanderson argues that while society certainly is "socially constructed," these social constructions are not arbitrary products of an autonomous culture.  Social constructions are constrained by the natural desires and natural conditions of human existence.  Human biological nature constrains but does not determine human cultural history and the choices of human individuals.  Consequently, a Darwinian social science must explain the universality of human natural desires and the variability that comes from variable socioecological conditions and variable temperaments of individuals.  Sanderson shows how that can be done.

Identifying me as a "Darwinian political philosopher," Sanderson accepts my list of twenty natural desires as delineating the most important features of evolved human nature.  But he does offer his own slightly altered version of my list: (1) a complete and long life, (2) health, (3) reproduction and parental care, (4) sexual mating, (5) familial bonding, (6) gender identity, (7) social ranking, (8) wealth, (9) political rule, (10) reciprocal exchange, (11) ethnic identity, (12) beauty, (13) aesthetic pleasure, and (14) religious understanding (2014, p. 382).

Comparing the lists, one can see that he has made some changes.  He has moved "health" from number 11 on my list to number 2. He has changed "justice as reciprocity" to "reciprocal exchange." He has added "ethnic identity" to the list. And he has omitted from his list seven of the desires on my list: (6) friendship, (10) war, (14) speech, (15) practical habituation, (16) practical reasoning, (17) practical arts, and (20) intellectual understanding.

I do not see the justification for omitting these seven, especially since all of these seven desires appear in one way or another in his writing.  He says that friendship could rightly be added to his list (2014, pp. 12, 383).  He writes about the evolution of war (2001, pp. 318-330; 2014, pp. 287-312) and of language (2014, pp. 27-32).  He suggests that intellectual understanding should be added to his list (2014, p. 383).

Sanderson agrees with me that the natural desires cannot all be satisfied at the same time, or even over a whole life.  And so people must rank these desires, and since individuals differ in their natural temperaments and abilities, they will differ in how they rank these desires.  So, for example, as Sanderson observes, Albert Einstein said that he had no need for money, power, or fame to be happy; and so he was not much moved by the natural desires for social ranking, wealth, or political rule.  Einstein said all he needed were his sailboat, his violin, and physics.  And since he spent most of his time on physics, he was clearly ranking his natural desire for intellectual understanding over the other desires (2014, p. 383).  For me, this shows the need for practical habituation and practical reasoning in organizing a life for the fullest and most coherent satisfaction of one's desires over a whole life.

Sanderson has moved me to make two changes in my list.  I have combined a complete life and health into one category.  And I have added ethnic identity to the list.  So now my twenty natural desires are (1) a healthy life, (2) sexual identity, (3) sexual mating, (4) parental care, (5) familial bonding, (6) friendship, (7) social status, (8) justice as reciprocity, (9) political rule, (10) war, (11) ethnic identity, (12) beauty, (13) property, (14) speech, (15) practical habituation, (16) practical reasoning, (17) practical arts, (18) aesthetic arts, (19) religious understanding, and (20) intellectual understanding.

This begins a series of posts on how Sanderson's survey of the evidence for a Darwinian science of human nature supports my list of twenty natural desires.

Tuesday, April 05, 2016

The Embodied Capital Theory of Life History Supports Locke on Parental Care in the State of Nature

Leo Strauss taught his students at the University of Chicago that any serious student of the history of political philosophy must assume the possibility that what the great philosophers have taught might be true.  Writers of the textbooks on the history of political philosophy--like that of George Sabine--had assumed the truth of "historicism"--that all the great philosophers have been so imprisoned by the cultural prejudices of their time and place that they could not see the truths about political life that contemporary readers can see today.  But Strauss argued that historicism is itself the great cultural prejudice of our time that cannot be affirmed as true without contradicting itself, and therefore serious thinkers must consider the possibility that the human mind can free itself of common opinions and apprehend what is simply true, and thus that the great philosophers--from Plato and Aristotle to Rousseau and Nietzsche--might help us to see some truths about human nature and human history that go beyond the largely unexamined opinions of our day.

Roger Masters was one of the students at Chicago who was persuaded by Strauss's argument, and Masters devoted himself to the careful study and translation of the writings of Jean-Jacques Rousseau, with the thought that Rousseau was one of those great philosophers who might teach something about the truth of human nature and politics.  Masters became one of the leading translators and scholars of Rousseau in the 1960s.  He was particularly interested in Rousseau's account of the state of nature and social contract reasoning as compared with Thomas Hobbes and John Locke.

Then, in the 1970s and 1980s, Masters began to study evolutionary science and Darwinian anthropology, with the thought that this science of human evolution might illuminate the debate between Hobbes, Locke, and Rousseau over the state of nature.  Masters thus became one of the first political scientists to apply Darwinian science to the study of political philosophy.

According to Rousseau, neither Hobbes nor Locke recognized that in the state of nature human beings were so completely solitary that they would have lived in a state of peace and equality without any dependence on other human beings.  Masters wrote this as his English translation of one of Rousseau's passages in the Discourse on the Origin of Inequality:
"Alone, idle, and always near danger, savage man must like to sleep, and be a light sleeper like animals which, thinking little, sleep so to speak all the time they do not think.  His self-preservation being almost his only care, his best-trained faculties must be those having s principal object attack and defense, either to subjugate his prey or to save himself from being the prey of another animal." (Rousseau 1964, 112)
This was published in 1964 in Masters' edition of The First and Second Discourses.  Then, in 1982, when Masters read Frans de Waal's Chimpanzee Politics, which describes the complex political lives of chimpanzees competing for power and alpha male dominance in small groups, Masters saw that this implied that the earliest evolutionary ancestors shared with chimpanzees and human beings were probably highly political animals.  He also saw that anthropologists studying the societies of human hunter-gatherers had shown the complex social order of these primitive human groups. Consequently, it seemed that biologists and anthropologists had shown that human beings in a state of nature could not have been utterly solitary, as Rousseau claimed. 

And if Strauss was right about taking seriously the possibility that the teaching of a great philosopher like Rousseau could be true, this must include the possibility that the teaching could be false.  Philosophers make empirical claims about human nature and human history that could be either confirmed or denied by scientific research.  So, Masters had to admit that Rousseau's teaching about the state of nature had been refuted by Darwinian science.  "Like chimps," Masters concluded, "humans are by nature social animals with innate political behaviors of a sort ignored by Rousseau in the passage I'd translated" (Masters 2013, 227).

I agree with Masters about this, because in a series of posts, I have argued that the evidence from evolutionary science and political anthropology allows us to judge the philosophic debate over the state of nature and to conclude that while Rousseau was mostly wrong, Hobbes was partly right, and Locke was mostly right.  This illustrates how the study of the history of political philosophy can become a biopolitical science.

Consider, for example, how Locke's account of the human family as the "first society" in the state of nature is confirmed by the "embodied capital theory" of the evolution of human life history, which is supported by lots of evidence gathered by Darwinian primatologists and anthropologists.

In the Two Treatises, Locke gives both religious and natural explanations for human familial bonding in the state of nature.  It shows the "wisdom of the great Creator" that He has created human beings with desires for monogamous marrying and for mothers and fathers jointly caring for their children (1970a, 86-89; 1970b, 77-80).  This can also be explained through the natural history of animal reproduction as adapted to the feeding niche for each species.  For some frugivorous animals who feed on grass and plants, whose offspring can survive shortly after birth without much parental care, Locke explains, mothers care for the offspring with no need for fathers to provide any parental care, and consequently there is no need for any enduring bond between the sexual mates.  But for those carnivorous animals who feed on meat from hunting, there is a natural need for an enduring pair-bonding of the sexual mates to provide biparental care.  If mothers cannot feed themselves and their offspring without the help of males, because they need the meat provided by male hunting, or if birth-spacing is short that mothers can often have multiple dependent offspring requiring prolonged care from both parents, then these animals will have a more enduring conjugal bond; and this is true for human beings.  As compared with other animals, human offspring are dependent on adult care for a long period of childhood, in which children cannot produce enough food to feed themselves.  During this period of dependence, offspring must be not only nourished but also educated, because complex human social life requires a prolonged period of social learning in which children learn the skills they will need to become productive adults.

In contrast to Locke, Rousseau argued that human beings in the "pure state of nature" were asocial and almost completely solitary animals.  Men and women encountered one another by accident and engaged in sexual intercourse whenever the desire moved them, and then they immediately left each other and felt no tie to one another.  Mothers nursed their children for a short time.  But as soon as the children could feed themselves, they left their mother, and they soon would no longer recognize one another.  So while the maternal attachment to children was the one social bond in the state of nature, it was only a momentary bond that created no enduring social recognition between parents and children and no support for the mother and child from the father (Rousseau 1964, 108, 112, 120-21, 130-31, 137, 142, 147, 216, 219).

In one of the longest notes in the Second Discourse (1964, 213-20)--note l--Rousseau quotes the entirety of sections 79-80 of Locke's Second Treatise, where Locke lays out his reasoning for monogamous pair-bonding and biparental care in the state of nature.  Rousseau denies the factual truth of Locke's claims about animal reproduction and parental care, and accuses him of making the same mistake that Hobbes made in projecting what we see in human beings today back into the state of nature. 

Against Locke, Rousseau insists that primitive human beings were totally frugivorous in their feeding and not at all carnivorous.  Mothers and children who feed on grass and plants can easily feed themselves without any need for meat from male hunters.  Furthermore, Rousseau argues that fact that human females have only two teats indicates that they rarely have more than one child at a time that needs care, and thus mothers and children have no need for help from the men.

Over the past 100 years, studies of human hunting-gathering societies and comparative studies of other primate and mammalian societies have provided evidence that Rousseau was mostly wrong, and Locke was mostly right.  This evidence shows that as compared with other mammals and primates, human beings show at least five distinctive traits.  The first four pertain to human life history.  Human beings have an unusually long lifespan.  They have also have an unusually long period of juvenile dependence on adults.  They show an unusual pattern of support for reproduction from older post-reproductive adults.  And they show male support of reproduction through the provisioning of females and their offspring.  The fifth distinctively human trait is unusually large brains that bring increased capacities for social learning, teaching, and thinking about cognitively challenging problems.  Human hunter-gatherers, who live in what the early modern philosophers called the state of nature, show all of these traits.

One persuasive evolutionary theory that fits all of this this evidence for these distinctively human traits is the embodied capital theory developed by Hillard Kaplan and his colleagues (Kaplan et al. 2000).  The main idea is that the human species show an evolutionary adaptation for a feeding niche based on high-quality, nutrient-dense, and difficult-to-acquire foods, which is a skill-intensive niche that requires extended learning through big brains.

Chimpanzees and other nonhuman primates feed mostly on leaves, small, unripe fruit, and large, ripe fruit, which constitutes over 90% of their diet.  Gathering this food requires so little skill and effort that young chimpanzees after they have been weaned can gather enough to feed themselves.  Chimpanzees do extract some food from nuts and insects in ways that require some skill that has to be learned.  And the males do engage in some hunting that requires some skill.  But the extracted food and the hunted meat is a very small portion of their diet, and the skills required for acquiring this food are not very complicated.

By contrast with chimpanzees, over 75% of the diet of human foragers is meat from hunting, which requires great skill that comes only from adult males who have learned those skills over a period of 30 years or more.  In contrast to leaves and fruit, meat is higher quality food, rich in protein, and highly concentrated, but it is also more difficult to acquire.  Hunted meat provides the nutrition necessary for the growth and maintenance of big brains that consume high levels of metabolic energy.  And it is these big brains that are necessary for learning the skills necessary for successful hunting.

Unlike chimpanzees, adult male human foragers must produce food for the feeding of women and children.  Human children consume more food than they consume until about age 20.  Human females consume more food than they consume throughout their childhood and their years of reproductive fertility.  Human females produce slightly more than they consume only after menopause and before old age.  Human females can have shorter birth intervals than apes do, because human females get food subsidies from adult male hunters, so that mothers can care for two or more children at a time.  Most of the production of food comes from adult males (ages 25-55) through hunting, who share their food with women and children.

Tracking and killing wild game of many different species is an intellectually challenging problem that takes many years of social learning with a large brain that requires many years of growth.  Consequently, both mothers and fathers must make many years of resource investments in the rearing and educating of their children before they can become productive contributors to reproductive fitness.

If this is the scientific description of the state of nature--of the original life of our earliest human ancestors--then Locke was mostly right, and Rousseau was mostly wrong.  This would then be an example of how Darwinian science can contribute to the study of the history of political philosophy by helping us to judge the claims that the philosophers have made as being true or false.


Kaplan, Hillard, Kim Hill, Jane Lancaster, A Magdalena Hurtado. 2000. "A Theory of Human Life History Evolution: Diet, Intelligence, and Longevity." Evolutionary Anthropology, 9:156-185.

Masters, Roger. 2013. "On the Relationship between Liberalism and Darwinism," in Stephen Dilley, ed., Darwinian Evolution and Classical Liberalism: Theories in Tension, 217-236. Lanham, MD: Lexington Books.

Locke, John. 1979. Two Treatises of Government. Edited by Peter Laslett. Cambridge, UK: Cambridge University Press.

Rousseau, Jean-Jacques. 1964. The First and Second Discourses. Translated by Roger D. and Judith R. Masters.  New York: St. Martin's Press.

Tuesday, March 29, 2016

Is the Demographic Transition the "Central Theoretical Problem of Sociobiology"?

If human beings have evolved to have a natural desire to care for children, as I have argued, it might seem strange that in modern industrialized societies, people tend to have small families.  One might expect that the increasing economic resources in such societies would allow people to satisfy their desire for children by having large families.  The decline in the total fertility rate in industrialized societies, which began in the 19th century, is called the "demographic transition."  Over the past 50 years, some social scientists have identified a second demographic transition, in which the decline in fertility in some of the richest societies has fallen below the reproductive rate necessary to replace the present generation, which suggests that possibility that the population of some socially successful groups will decline to the point of extinction. 

This might seem to deny my claim about parenting as a natural desire.  More generally, it might seem to deny the claim of sociobiology that human social behavior has evolved to favor genetic fitness.  Among many animal species and among human beings in most societies until the past two centuries, the most dominant human beings have tended to be more reproductively successful (Ellis 1995; Betzig 1986).  But in the most developed societies today, the rich and powerful tend to have low fertility rates, and it's the lower class people who have higher fertility rates.  That social success does not correlate with reproductive success after the demographic transition has been identified as the "central theoretical problem of sociobiology" (Vining 1986).

And yet I see the demographic transition as a natural expression of the prudent flexibility of human beings in adapting their parental desires to changing ecological circumstances.  Because of the natural variability in human temperament, some human beings will choose to be childless.  But most human beings in all societies will have a strong natural desire to care for children.  In the socioeconomic circumstances of modern industrialized and technologically advanced societies, parents will want to have small families, so that they can invest resources in their own education, in their careers, and in the education of a few children, and so that those children can become socially successful adults.  Most parents will desire to have no more than two or three children, and where mortality rates are low, this will be enough to sustain current population levels. 

In some cases where the costs of children have become very high, fertility rates have fallen below replacement levels.  In most cases, I suspect, these fertility rates will eventually return to the level of replacement.  If they do not, then those population groups with such low levels of reproductive success will eventually disappear, and thus biological evolution by natural selection will reassert itself.

The total fertility rate (TFR) is a measure of an imaginary woman who passes through her reproductive life subject to all the age-specific fertility rates for the ages 15-49 that were recorded for a given population in a given year.  So this rate is the number of children a woman would have if she was subject to prevailing fertility rates at all ages from a single given year, and if she survived throughout all her childbearing years. 

According to United Nations data, the average TFR for the world was 4.95 for 1950-1955, 3.84 for 1975-1980, 2.79 for 1995-2000, and 2.36 for 2010-2015.

If there were no mortality until the end of a woman's childbearing years, the replacement level of TFR would be around 2.0.  The replacement fertility rate is close to this for most industrialized countries.  For the global average, the TFR at replacement is about 2.33.

In the U.S., the TFR was at 2.1 in 1930-1934.  It peaked at about 3.8 in the late 1950s (during the baby boom).  Today, the TFR for native born Americans is below replacement and above replacement among immigrant families.  But the fertility rates of immigrants decrease sharply in the second generation, which is correlated with greater education and income in the second generation.

The average TFR for the European Union is 1.59.  The lowest TFR for any country today is .81 for Singapore.

The lowest TFR in recorded history is .41 for the Xiangyang district of Jiamusi city in China.  Outside China, the lowest TFR ever recorded was .80 for East Germany in 1994.  The East German case is an extraordinary example of how fast people can change their fertility decisions in response to changing historical conditions (Conrad, Lechner, and Werner 1996).  Both West and East Germany had a post-war baby boom that peaked at a TFR of 2.5 in 1965.  But by the early 1970s, the TFR had fallen to around 1.4, well below replacement levels, and one of the lowest fertility rates of any society in the world.  But then the Honecker regime established pronatalist policies for East Germany, including financial incentives and social benefits for marriage and births, and the TFR for East Germany rose to 2.1, while that for West Germany remained at 1.4.  Then, after the fall of the Berlin Wall in 1989 and the reunification of Germany in 1990, the TFR for East Germans dropped well below that for West Germans, apparently because East Germans thought the future socioeconomic circumstances would not be favorable for bearing children. 

Today, the TFR for the East Germans is at the level for West Germans--1.44--which is well below replacement levels.  Some Germans have worried that if this continues into the future, the native born German population could be extinguished, and the German population would be composed totally of recent immigrant groups. 

Remarkably, there is no single explanation for the demographic transition that is generally accepted among social scientists.  There are at least three theories that have been proposed.

One theory proposed by Marvin Harris and others is that people adjust their fertility according to the economic value of children's labor.  In agricultural economies, the reasoning goes, children are valuable workers for farm families, and consequently couples will want to have many children.  But in industrialized societies, children have little value as laborers, and they become costly to rear, so that couples choose to limit the number of their children.

The problem with this theory is that there is little evidence that in high fertility societies, wealth flows from children to parents, because even in such societies, children are consuming more than they are producing, and so they are costly to rear.

Another theory is that low fertility societies are those in which women have more autonomy, and since the burden of producing and caring for children is usually greater for women than for men, empowered women will choose to have fewer children than when men are in control.

But while there is evidence of some correlation between low fertility and female empowerment, it often seems that female empowerment is more the effect than the cause of low fertility (Sanderson 2001, 168-76; Sanderson and Dubrow 2001).  As the fertility rate drops, women have greater freedom to pursue the education and career activities that empower them.

A third theory seems to me to be most plausible in being supported by extensive evidence (Arnhart 1998, 116-118).  It's what Hillard Kaplan and his colleagues have called "the embodied capital theory of life history evolution" (Hill 1993; Kaplan 1996; Kaplan et al. 2002; Kaplan et al. 2003; Lancaster 1997).

This theory shows how a Darwinian view of parental investment can explain the cultural variation in parental behavior.  Human parental investment in children is neither genetically fixed nor culturally arbitrary.  Parental investment is not genetically fixed, because the human desire for parental care manifests itself invariable ways in response to the variable ecological conditions of the physical and social environment.  And yet parental investment is not culturally arbitrary, because its variability follows a predictable pattern as human beings strive to satisfy their natural desire for parenting in diverse circumstances.  As Aristotle would say, parental care of children is natural, but prudence dictates that the best way to satisfy that natural desire varies to conform to the conditions in which human beings happen to find themselves.

Patterns of parental investment emerge from a series of decisions involving trade-offs that all animals (including human beings) must make (either consciously or unconsciously) over the course of their life history.  These trade-offs require allocating scarce resources (such as time, energy, and risk) between competing activities. 

The first trade-off is between somatic effort (investing resources in the growth, development, and maintenance of the individual animal) and reproductive effort (investing resources in the individual animal's offspring).  The second trade-off is between two forms of reproductive effort--mating effort (investing resources in the search for mates) and parental investment (investing resources in the care of offspring).  The third trade-off is between two forms of parental investment: one stresses the quantity of offspring (investing in a large number of offspring but with each receiving few parental resources), and another stresses the quality of offspring (investing in a lesser number of offspring but with each receiving extensive parental resources).  All animals must make such choices (consciously or unconsciously), and whether one choice is better or worse than another depends on the variable ecological conditions of their lives (Emlen 1995).

Like other animals, all human beings must decide how much to invest in themselves as compared with their children, because producing and caring for children is costly.  All human beings who decide to reproduce must then decide how much to invest in finding mates as compared with investing in the children produced by mating, because directing resources to finding new mates can mean decreasing the resources available for the children produced through earlier mating.  All human beings who decide to invest care in their children must then decide whether to divide their resources among many children or concentrate their resources on a few children, because children typically consume more parental resources than they produce, and therefore any increase in the quantity of children requires some reduction in the quality of the resources available for each child.  Deciding between the quantity and quality of children will be influenced by the mortality rate, because if many children die before they reach mature adulthood, parents will be less inclined to invest great resources in them.  The low mortality rate in modern industrialized societies is one reason parents can invest their resources in a few children without much fear of losing the return on their investment.

The differences in how people make these decisions manifest the complex interactions of differences in individual temperament, individual history, sexual identity, and social history.  Although most human beings will become parents at some time in their lives, a few will never become parents, either becaue they lacked the opportunity (through infertility or failure to find a suitable mate), or because by temperament and circumstances their parental desire was weak in comparison with other desires.  Men will tend on average to invest somewhat more in mating effort and somewhat less in parental care than do women on average, because while a man can impregnate many women, women cannot be impregnated more than ten to twenty times in their lives.  Yet despite this difference in tendency between men and women, most men desire the social stability that comes from mating with one woman or a few women and then investing great paternal care in the children produced.

The choices human beings make about parental investment will also reflect social history, because the likelihood that one choice is better than another in satisfying the natural desire for parental cadre will depend on social conditions that determine the costs and benefits of alternative reproductive strategies.  One example of such social variability is in the choice between the quantity and quality of children.  As a general rule, animals in good condition (having good health, plentiful physical resources, or high social status) tend to produce more offspring than animals in bad condition.  This seems to have been true for human beings throughout most of their history: the healthier, wealthier, and more powerful people have tended to have more children that survive to adulthood.  But now a new pattern has emerged.  People in modern, industrialized societies tend to produce fewer children on average than people in less developed societies.

One can explain this in Darwinian terms.  In the developed societies, the economic and social success of children depends ever more on their acquired technical skills and educational training, so that as adults they can compete for jobs that require special talents and knowledge. Consequently, rearing successful children in such societies requires that parents make increasingly costlier investments in the education of their children.  And as the cost of children has thus increased, the quantity of children demanded by parents has decreased, because parents now express their natural desire for parenting successful children by investing more resources in fewer children, thereby choosing quality over quantity in their children.

Moreover, for human beings to be able to invest so much in their children, they must first invest time and energy in their own education and career development and in the search for suitable mates.  Consequently, successful people in modern developed societies must often delay their marriage and having children, and thus the average ages for getting married and having the first child have risen.  When women do this, they sometimes reach the end of their reproductive years, and so produce fewer children than they would have desired.  It's likely that one reason for the total fertility rate falling below replacement levels is that couples who desire two or three children delay marriage and reproduction for so long that the women reach the end of their physiological fertility sooner than they had expected.  Then couples must rely on fertility treatments or adoption to satisfy their parental desires.

This shows the kinds of decisions that human beings must make as they adjust their patterns of parental investment to be adapted to the ecological circumstances in which they find themselves.  A natural human desire for parental care will be culturally and individually variable because of the variability in the physical and social conditions of parental care and in individual personality.  Consequently, the evolutionary behavioral ecology of parental care must move through three levels of analysis--the genetic history of the species, the cultural history of the group, and the individual history of those making their decisions about parenting.

I need to say more about "embodied capital theory," which I will do in my next post.

Sunday, March 20, 2016

The Big History of Morality: The Pursuit of Happiness from Stromatolite Cooperation to the Global Morality of Sustainability

Lower Proterozoic Stromatolite Fossil from Bolivia

Stromatolites at Shark Bay, Western Australia

"Big history" is the term coined by David Christian for the history of everything in the universe from the Big Bang to the present, and including plausible speculations about the future of the universe.

Modern academic history has traditionally identified the beginning of history with the invention of writing about 6,000 years ago, because this began the written records that historians have needed to reconstruct history.  Consequently, such history has been the history of literate peoples, and everything prior to the invention of writing has been considered "prehistory."

David Christian and other proponents of big history--such as William McNeil, Fred Spier, Dan Smail, Cynthia Brown, and Craig Benjamin--have argued that this is an unreasonably narrow view of history that ignores the fact that modern evolutionary science can reconstruct the entire history of the universe through empirical evidence (such as fossil evidence on Earth and astronomical data from beyond the Earth) that does not depend on written records.  Moreover, there is a great intellectual benefit in big history in that it provides a grand interdisciplinary integration of the natural sciences, the social sciences, and the humanities, which looks like what I have called "Darwinian liberal education."

Throughout history, human beings have constructed universal histories of the universe through religiously based creation stories (like that in the Bible or in Plato's Timaeus), which depend on religious beliefs in supernatural activity that cannot be confirmed with empirical evidence.  But now modern science can construct a secular universal history based on inferences from empirical evidence.  As suggested by some scientists like Eric Chaisson, some of the proponents of big history argue that the general theme of this universal history is the evolution of complexity made possible by the flow of energy through matter.

The first big history, in ancient Rome, was Lucretius's On the Nature of Things, a history of the universe based on an Epicurean science of evolutionary atomistic materialism.  Although Lucretius professed to believe that gods existed, they exercised no creative power over the universe, and they were indifferent to human affairs.  Later, in the first half of the 19th century, Alexander von Humboldt's Cosmos: A Sketch of a Physical Description of the Universe and Robert Chambers's Vestiges of the Natural History of Creation provided modern scientific accounts of the natural evolution of the universe from the beginning to the present.  Humboldt never mentioned God or divine activity.  Chambers invoked God as the First Cause of nature, but his natural history of the universe did not require miraculous acts outside of the laws of nature.  Big history continues this tradition of writing, but proponents of big history can claim that the scientific knowledge accumulated over the past two centuries allows them to base their history on the best empirical science.

The religiously based universal histories provided a moral teaching as grounded in a divine cosmic order:  in learning how they were created by God and how they were commanded to obey His laws, human beings recognized a moral law for their lives derived from divine law.  By contrast, the scientifically based universal history as reconstructed by big historians does not seem to provide any moral teaching, because modern science must be value-free in explaining what is the case, but without explaining what we ought to do.  Thus, it seems that morality must be a matter of personal choice for each individual without any guidance from big history.

But what happens when many people in the modern world no longer find creation stories and religiously based morality credible, or when globalization brings ever more people into contact with others who do not share their religious world views?  So, for example, how do we resolve the conflicts that arise when radical Islamists declare holy war against the infidels, because they believe that they are fighting the Last Battle that will bring the end of history?

Among the proponents of big history, Fred Spier has begun to argue that big history must include the big history of morality, and that this might support a scientifically grounded view of morality.  Spier's writing on this include a few passages in his Big History and the Future of Humanity (2015a), his unpublished paper on "Morality in Big History" (2015b), and a published article on "Pursuing the Pursuit of Happiness: Delving into the Secret Minds of the American Founding Fathers" (Social Evolution & History, vol. 12, no. 2, September 2013, pp. 156-182). 

Although Spier and I disagree on some points, I am interested in his reasoning,  because it sounds a lot like what I have long argued for--a biological ethics rooted in human nature as shaped by evolutionary history.

In considering how morality could be derived from nature, Spier has looked to Paul-Henri Thiry Baron d'Holbach (1723-1789), who was a French atheist philosopher of German descent, who led a famous salon in Paris where many of the leaders of the Enlightenment met for discussions.  In his book Systeme de la nature (1770), he argued that an atheistic morality could be rooted in the natural pursuit of happiness, because people could recognize that living a virtuous life in cooperation with others was necessary for one's happiness.  Spier thinks there is some evidence that Thomas Jefferson's appeal to the "pursuit of happiness" as a natural right in the Declaration of Independence shows the influence of d'Holbach's writing.

If we define moral rules as the rules for the successful cooperation necessary for the pursuit of happiness, Spier argues, then we can see the big history of morality as beginning with the first forms of social cooperation among living beings.  The evolution of cooperation for improving survival and reproduction might have emerged more than 3.5 billion years ago, when single-celled microorganisms gained some advantage in the struggle for survival by hanging together.

The oldest fossil evidence of life is stromatolite fossils.  A stromatolite (literally, ‘layered rock’) is a solid structure created by single-celled microbes called cyanobacteria (blue-green algae). The photosynthesizing cyanobacteria form colonies and trap sediment with their sticky surface coatings. The trapped sediment reacts to calcium carbonate in the water to form limestone. 

Microbial mats can still be seen today in places like Shark's Bay in Western Australia.  Hanging together allows these microorganisms to stick to the rocks in shallow sea water without being washed away by the tides.  By hanging together, these microorganisms are cooperating with one another for their mutual benefit.  And while we might not see this as morality in the strict sense, Spier observes, we might see this as at least "incipient moral behavior" (2015b, 20).

Cooperation requires communication, so that organisms can coordinate their behavior.  Microorganisms, plants, and animals use chemical signals to do this.  Animals with brains and nervous systems can create mental images of their physical and social environments through which they can form social rules of cooperation.  Through language, human beings can create and communicate complex cultural rules of cooperation.  Like other social animals, human beings cannot survive and reproduce successfully without learning the rules of cooperation and competition developed within their social groups.  Ultimately, their motivation to do this is their desire for happiness.

Spier surmises that there must be some form of chemical reward for cooperation that supports feelings of happiness.  He notes that some scientists have reported that a neurotransmitter called hypocretin increases when people are happy and decreases when they are sad.  He wonders whether this chemical signal could be a biological reward for doing the right thing, and if it is very old, this could be the ancient biochemical mechanism for the pursuit of happiness, which might have appeared first among microorganisms (2015b, 21-22).

Spier's reference to the neuropeptide hypocretin is remarkable to me, because the other common name for this neuropeptide is orexin.  This word was coined in 1998 from the Greek word orexis, a Greek noun for "desire" or "appetite" that was coined by Aristotle from the Greek verb orego, which means "to reach out."  Desire, Aristotle thought, was the mind's "reaching out" for something in the world.  For Aristotle, in The Movement of Animals, desire is the general term for all kinds of longing or striving, including physical appetites, social emotions, and intellectual yearnings.  I have used the word "desire" in the same way as a general term for all kinds of psychic impulse or inclination.  With that sense in mind, I have defended a natural morality of informed desire: the good is the desirable, and reason judges how best to satisfy the desires in the most harmonious way over a whole life.  There are at least 20 desires of evolved human nature, and so we can judge our moral standards for how well they satisfy those desires.

Spier points in this direction when he refers to "standards of desired, or at least acceptable, behavior", "desirable standards of conduct," and moral standards judged as "the most desirable" (2015b, 8, 20, 29).

In their voluntary activity, animals move to satisfy their desires in the light of their information about opportunities and threats in their particular circumstances.  Like other animals, human beings move to satisfy their desires in the light of their information about the world  They have a natural range of desires that they share as members of the human species and that distinguish them from other animals.  The human pattern of desires includes appetitive desires such as hunger and sexual lust, social desires such as anger, love, and honor, and intellectual desires such as curiosity and wonder.

Human beings have uniquely human capacities for language and deliberation that allow them to gather and assess information about the past, the present, and the projected future, so that they can consciously formulate long-term plans of action based on their conceptions of happiness (a whole life well-lived).  Big history is part of this, because a scientific history of everything from the beginning of the universe could help human beings to plan for the future in the pursuit of happiness.

So, for example, Spier thinks big history can help us to see that the future happiness of humanity depends upon an environmentalist morality of sustainable development for the Earth.  If preserving the human species and human civilization depends upon the availability of matter and energy to support the complex order of human life, and if human beings are now nearing the exhaustion of the nonrenewable resources of matter and energy necessary for human life, then the most critical moral question today is whether human beings on planet Earth can learn to cooperate in reaching environmental sustainability based on renewable energy sources.

I am not persuaded, however, that Spier's environmentalist pessimism is plausible.  And I will explain why in a future post.