Wednesday, August 15, 2012

Does Oxytocin Solve the Adam Smith Problem?

Paul Zak thinks that oxytocin solves the Adam Smith Problem. 

As I have indicated in some previous posts, this problem in interpreting Smith arises from the apparent contradiction between the primacy of morality in Smith's Theory of Moral Sentiments and the primacy of self-interest in Smith's Wealth of Nations.  The significance of this problem is that it points to a fundamental problem in the social sciences.  Are human beings naturally social, naturally selfish, or some tense combination of both?  Does our morality show our naturally social side, while our economic behavior shows our naturally selfish side?  Is morality concerned with the world as we would like it to be, while economics is concerned with the world as it really is?  Do modern market societies corrupt our morals by teaching us that greed is good?  Or do efficient markets depend upon good morals?

Zak's answer is that on the whole, markets and morals are mutually dependent: morals support markets, and markets make us more moral.  Moreover, he argues, the morality of markets arises from the evolved biological nature of human beings, particularly as manifest in the neurophysiological action of oxytocin, which is the "moral molecule" that sustains our social connectedness as moral animals.

This solves the Adam Smith Problem, Zak believes, because oxytocin constitutes the biological foundation for both the morality of The Theory of Moral Sentiments and the economics of The Wealth of Nations.  In his new book--The Moral Molecule--Zak explains this as his eureka insight: "What if oxytocin was, in fact, the chemical signature for that elusive bonding force Smith had called mutual sympathy?  Then, thinking back to my research on the prosperity-enhancing power of trust, I had to laugh.  What if this 'Moral Molecule'--if that's what oxytocin was--is also an essential element in what Smith called the wealth of nations?" (24).

In general, I am largely persuaded by Zak's argument, which I will summarize in this post.  I welcome his argument as reinforcing what I have defended as Darwinian classical liberalism, because he helps to explain the neurophysiology of morals and markets as evolutionary unintended orders.  As is usually true for liberal social theory, Zak stresses the importance of order that arises "bottom-up" rather than "top-down." 

But I also see at least four kinds of difficulties in his research, which I will sketch out in a second post.

Oxytocin is a nine amino acid mammalian hormone that also acts as a neurotransmitter in the brain.  When Henry Dale discovered it in 1906, he gave it the name derived from Greek that means "quick birth," because it facilitates uterine contractions during birth.  It also facilitates the ejection of milk when a mother's nipples are stimulated.  And it generally seems to be associated with maternal bonding to offspring and sexual bonding to the father.  In prairie voles, it promotes monogamous attachment.  So it seems that oxytocin has evolved primarily among social mammals to promote reproduction, parental care, and conjugal bonding.  That's why oxytocin comes up in my chapter on the desire for parental care in Darwinian Natural Right.

Zak became internationally famous when he reported research suggesting that far from being restricted to reproductive functions, oxytocin was associated with social bonding of all kinds.  Since hugging appears to stimulate surges of oxytocin, he now advises that we can spread peace and love by hugging one another at least eight times a day.  That's why he's popularly known as "Dr. Love."

As an economist who has turned to neuroscience to explain behavioral economics, he has established himself as the founder of "neuroeconomics."

His most important experimental evidence comes from having people play the Trust Game and then measuring the activation of oxytocin in them.  In the Trust Game, two players are given some money (say, $10 each).   If the A-player gives some of his money to the B-player, whatever is given will be tripled.  The B-player can then either keep all the money he has, or he can share some of it with the A-player.  Whatever money the A-player gives away is a measure of his trust in the B-player.  Whatever money the B-player gives back is a measure of his trustworthiness.

If these players were rational maximizers of their self-interest, neither player would share his money with the other.  The A-player would not be trusting, and the B-player would not be trustworthy.  But then they both would suffer, because they would walk away with less money than they would if they could enjoy the gains from mutual exchange.

In fact, experiments with this game suggest that most players are not purely selfish.  Typically, about 90% of the A-players share some of their money with the B-players; and 95% of the B-players respond to this generosity by sharing with the A-players.  So it seems that there is enough trust and trustworthiness for most human beings to be generous reciprocators, and thus they live by the Golden Rule.

Zak's claim is that this Golden Rule reciprocity is facilitated by oxytocin.  When the A-players are generous in their sharing, the B-players tend to respond with generous sharing, and the B-players show a surge of oxtocin in their blood samples.  If the sharing by the A-player is not intentional, because it is determined by a random process (drawing a numbered ball from an urn), then the B-players don't show a surge in oxytocin.  So it seems that when people are trusted to do the right thing, they feel a pleasing surge of oxytocin that makes them want to really do the right thing and thus show that they are trustworthy.

Of course, it's a little more complicated than that.  First, Zak explains the "Human Oxytocin Mediated Empathy" (HOME) circuit: surging oxytocin (seek connection) causes surging serotonin (reduced anxiety) and surging dopamine (reinforcing brain reward).  Then, he explains the "Oxytocin Virtuous Cycle":  oxytocin promotes empathy, which promotes morality, which promotes trust, which promotes more oxytocin, in a feedback loop.  And, finally, he explains the physiological connection between morals and markets by arguing that nations showing higher levels of trust also show higher prosperity, and oxytocin supports this insofar as oxytocin supports the morality of trust.

But then he introduces another level of complexity coming from the balance between oxytocin and testosterone.

Zak reports that in every experiment he has ever run, the women show higher surges in oxytocin than do the men.  The men have higher levels of testosterone than women, and this prompts male-typical behavior.  Testosterone is an antagonist of oxytocin, because testosterone blocks the binding of oxytocin to its receptors. 

Testosterone is from Mars.  Oxytocin is from Venus.

Testosterone promotes the punishment of cheaters.  And in behavioral games like the Trust Game and the Ultimatum Game, men are more inclined than women to severely punish cheaters, even when the punishment is costly to the punisher.  So what Samuel Bowles and Herbert Gintis identify as "strong reciprocity" might be more evident among men than among women.

Moreover, testosterone also promotes the aggressive defense of one's group  against outsiders, and thus the evolution of testosterone might be tied to the evolution of war.

In the evolution of traits that favor survival and reproduction, Zak reasons, it's best to have a balance between testosterone (as promoting competition and aggression) and oxytocin (as promoting cooperation and empathy).  This supports what Bowles and Gintis call "parochial altruism":  through group selection in war, human ancestors evolved to cooperate within groups altruistically to better compete with outsiders from other groups.

Zak advises that "balance is best," because "humans are wired to be both trusting and skeptical, nurturing and punishing, competitive and cooperative, because each of these opposing forces can contribute to survival" (90, 93).  Deciding how best to achieve that balance requires judgment and thus indicates the role of reason.

Like Adam Smith and the contemporary proponents of evolutionary moral psychology, Zak emphasizes the importance of emotion or sentiment in morality, and thus rejects the rationalist transcendentalism of the Platonic or Kantian tradition of moral philosophy.  But he also recognizes that reason has a role to play, and thus he shows what Michael Frazer has called "reflective sentimentalism":  moral psychology is seen as an expression of the whole human mind, reason as well as emotion. 

The emotions are rational in the sense that they are responses to the circumstances of life, and we can judge whether those emotions are appropriate responses or not.  Smith's impartial spectator procedure allows for this interaction of reason and emotion.  And while some evolutionary psychologists of morality like Jonathan Haidt tend to present moral reasoning as the slave of the moral emotions, others follow Smith in seeing a complex interplay of reason and emotion in moral judgment, and in this way they also follow in the tradition of Edward Westermarck's Darwinian moral psychology.

This important role for reason in the Darwinian psychology of morality is manifested whenever Zak speaks of how "a positive social stimulus prompts the release of oxytocin," which implies some kind of cognitive judgment of the social circumstances, or when he speaks of the role of the prefrontal cortex of the brain in modulating the effects of oxytocin (38, 58, 62, 154).  For example, while we might feel empathy for homeless adults or drug addicts, our empathy might be lessened if we believe that they are responsible for their situation (66).

This role of reason frees us from what might otherwise look like a reductionistic biological determinism that denies our moral responsibility.  As rational animals, we have the capacity to judge our emotional impulses in the light of past experience and future expectations, and thus to correct those impulses if they are inconsistent, inappropriate, or harmful.  That's the ground for our moral freedom.

And yet, reason alone cannot move us to do what is right if we are not moved by the moral emotions that are typical for most human beings.  A few human beings might be so flat in their moral emotions that they lack the motivation for normal morality.

Like all animals, the traits of the human species are highly variable, and that individual variation can be either inborn or acquired.  So even if there is a physiological basis for morality in oxytocin that is typically expressed in most individuals, some individuals will deviate from this central tendency.  Consequently, Zak's experimental research shows that while most human beings most of the time show a natural human desire for social connection that sustains moral order, some individuals are disconnected from their fellow human beings, and a few are so profoundly disconnected that they cannot live a normal social life.

Zak explains these disconnected individuals as victims of either abuse, bad genes, or bad ideas.  The victims of childhood abuse can show a lack of emotional responsiveness to others that comes from a shutting down of their oxytocin receptors.  Autistic individuals appear to show innate disabilities in developing the social skills that depend on oxytocin and social attachment.  The most extreme form of Oxytocin Deficit Disorder might be psychopathy--the anti-social personality disorder that arises from a lack of those moral emotions that move most of us to conform to those moral norms required for social life.  Sometimes physical injuries to the brain can induce the symptoms of these disorders. 

All of these factors for explaining moral deviance have been recognized previously by thinkers like Aristotle, Thomas Aquinas, Smith, Darwin, and others.  But the research of Zak and others helps us to understand the underlying neurophysiology of such deviance.

Some religious believers would object to Zak's Darwinian science of morality, and they would say that what scientists call moral deviance is actually sin, and that the only adequate response to such human evil is to recognize the authority of God's moral law and of the rewards and punishments to come from God's final judgment.

Zak was raised by strict Catholic parents.  His mother was originally a nun.  And although he is not a religious believer, he is not one of those "new atheists" (like Richard Dawkins) who scorn religion.  Rather, like David Sloan Wilson and other Darwinian scientists who look for a scientific explanation of religion, Zak applies his scientific understanding of how oxytocin, testosterone, and other biological mechanisms shape human thought and action to explain religion.

He speculates that religion is an natural adaptation shaped by the evolutionary history of the human social brain and group selection in warfare.

As social mammals with powerful intellects for imaginative projection, we want to connect to beings outside ourselves.  Oxytocin helps us to to do that--to project ourselves into the minds of others, which manifests what Smith identified as the natural desire for mutual sympathy.  This propensity to step outside ourselves--this longing for ecstasy--inclines us to connect to something bigger than ourselves that will love us and care for us.  We feel lonely in the cosmos, and we want to return to the home from which we came.  This, Zak suggests, is the evolved psychological inclination that leads to religious belief.

Although this suggestion is speculative, there is some evidence for it.  As Zak indicates, the history of religious texts and religious experiences is full of eroticism and love.  Consider the orgasmic ecstasy of Saint Teresa of Avila or the powerful teaching that "God is love."  "The cosmos works the same way a human family does--with love and caring" (145).

Although Zak does not mention it, I think the Old Testament book of the "Song of Songs" or "Song of Solomon" is a remarkable testament to religious eroticism.  It is one of the most beautiful erotic poems ever written.  It was accepted into the canon of the Bible, because such sensual imagery of erotic love was thought to capture the deepest longings of the believer for ecstatic union with the divine.

Zak's explanation of religious psychology as the anthropomorphic projection  of the social brain is similar to the explanation from Justin Barrett, Jesse Bering, and others for religion as rooted in a "Hyperactive Agency Detection Device" (HADD).

Moreover, Zak also adapts the group selection explanation of religion, which originated with Darwin and which has been elaborated by David Sloan Wilson.  The very term "religion" means a binding together, and indeed religion reinforces loyalty to the community of believers, while also fostering hostility to the unbelievers.  This can promote religious cruelty.  But it can also promote self-sacrificing service to the religious community.

This might explain why Smith appealed to a theology of divine intelligent design to reinforce his moral teaching.  The rules of morality become powerful when they are regarded as the laws of God, enforced by rewards and punishments in the afterlife.  Furthermore, Zak's explanation of the evolutionary longing for God the Father might illuminate Smith's remark about how resistant human beings are to the idea of a "fatherless world."

And yet God is complex.  The Jehovah of the Old Testament is vengeful and punishing.  The Jesus of the New Testament is loving and peaceful.  Zak argues that the Bible thus captures the dualistic balance in human moral motivation--manly punishment rooted in testosterone and womanly love rooted in oxytocin--because the Hebrew God and the Christian God reflect this deep duality in human moral psychology.

So how does all of this solve the Adam Smith Problem by reconciling Smithian morals and Smithian markets?

Zak's answer depends on combining his earlier research on the connection between trust and prosperity and his later research on oxytocin as supporting trust as the empathetic ground of morality.  What Smith identifies as the "propensity to truck, barter, and exchange" is actually moral in the sense that we must care about the needs of others if exchange is to be successful.  For you to give me what I want, I must give you what you want.  And that means that I must serve the needs of others, so that they will serve my needs.  Ultimately, trade is in the self-interest of each trader.  But a purely selfish trader who cares not at all for the interests of others, and who is willing to cheat others whenever possible, is not likely to be a successful trader for very long.

Zak's account of how oxytocin supports trust, and thus supports the gains from trade when the traders trust one another, provides a neurophysiological basis for the link between morals and markets.

Two kinds of evidence are especially important for this idea of "moral markets."  One is the evidence from international survey research that the nations with the greatest wealth tend to be the nations whose citizens report the highest levels of trust in one another.  When most people are trusting and trustworthy most of the time, it is easier for them to make deals with one another, and then carry out their contractual obligations without falling into endless disputes that make trade inefficient.

The second important kind of evidence comes from the cross-cultural research of Joseph Henrich and his colleagues (including Bowles and Gintis) in administering experimental games with small-scale groups in fifteen different cultures around the world.  In the past, most experimental game research was conducted with subjects from industrialized Western cultures, with a heavy concentration on American college students.  As one might have expected, these non-Western individuals in foraging and pastoral tribes behaved rather differently. 

For example, previous experiments with the Ultimatum Game showed a general pattern in which most proposers would offer something close to a 50% split of the money, and most responders would reject any offer less than 30% of the pot.  A tribe in the Peruvian Amazon called the Machiguenga behaved very differently.  Their offers averaged 26%, and less than 5% of the offers were rejected.  The researchers considered many  possible factors to explain this.  But finally they settled on one prime factor--"market integration" or the extent to which a group derives household calories from purchasing in a market as opposed to calories derived directly from nature by their own labor.  The Machiguenga were self-sufficient in providing for their needs without having to trade with others.  It seemed, then, that the experience of trading fosters expectations of fair dealing between the trading partners, and this promotes moral norms of trust and reciprocity.

Zak concludes from this that on the whole, markets make us more moral than we would be otherwise.  Contrary to the cartoonish image of capitalism as promoting the idea that "greed is good," the most efficient markets are moral markets.

Zak sees this as ultimately sustaining Smith's position. "When you read his work as a whole, as opposed to a few selected paragraphs, you find him making the case that the pursuit of self-interest can indeed benefit all, but only so long as it takes into account the mutual sympathy that leavens the contrary forces that are almost always at work in us, namely, greed and aggression" (168).

Although I find all of Zak's reasoning fascinating and most of it persuasive, I do see some difficulties that I will explain in my next post.

"Wikipedia" has a good article on oxytocin.

Zak's TED lecture is an engaging introduction to his argument.

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