Thursday, November 29, 2012

Incest in Ancient Egypt and Persia: A Westermarckian Response to Paul John Frandsen

Six years ago, I wrote a post entitled "So What's Wrong with Incest?"  Amazingly, every week since then, that post has been one of the top two or three posts in the number of pageviews at my blog.  Apparently, lots of people are troubled by incestuous thoughts, and they are Googling the Internet to find some help in understanding their feelings.  One can see that in some of the comments on my post.

I was disturbed to learn from one of my students that my post on incest can be found on a website for incest pornography, where it is presented as defending incest!

The purpose of my post was to summarize some of the reasoning of Edward Westermarck for explaining the Darwinian evolution of the incest taboo, which elaborates an idea briefly suggested by Darwin himself. 

I first began thinking about Westermarck and incest in 1998, when I lectured at a conference in Helsinki, Finland (Westermarck's homeland), on Westermarck's legacy.  There I first met Arthur Wolf, the leading defender of Westermarck's theory of incest, and other younger scholars like Debra Lieberman, who became a leader in the field.

Westermarck argued that if close inbreeding tends to increase the probability of producing offspring with inherited physical and mental defects that lower the chances of survival and reproduction, then we might expect that natural selection would favor adaptations for avoiding such inbreeding.  And one way of doing that would be to favor a mental propensity to feel disgust towards the thought of having sex with those among whom one has been reared from early childhood.  Typically, this would create a sexual aversion towards close family members.  This emotional disgust towards incest could then be generalized across a society as an incest taboo. 

Westermarck developed this as a Darwinian theory of the incest taboo that would illustrate a general Darwinian theory of morality as rooted in evolved moral emotions.  This Westermarckian theory has become one of the best examples of evolutionary moral psychology.

In my book chapter on "The Incest Taboo as Darwinian Natural Right," I explained why I think Westermarck's theory is persuasive, particularly when one considers the scientific evidence and arguments for it as summarized by Arthur Wolf in Sexual Attraction and Childhood Association: A Chinese Brief for Edward Westermarck.

There are lots of objections to Westermarck's theory, and I tried to answer them in my book chapter.  But I did not say enough about the objection that the incest taboo cannot be natural, because incest and incestuous marriages have been common in some societies, such as ancient Egypt and Persia.

The evidence for this objection has recently been surveyed in Paul John Frandsen's book Incestuous and Close-Kin Marriage in Ancient Egypt and Persia.  But while I find Frandsen's book fascinating, I am not persuaded by his general argument, because he has not shown that the evidence he presents refutes Westermarck's theory.

Although Frandsen mentions Westermarck and suggests that his book refutes Westermarck's theory, he shows no knowledge of the details of Westermarck's work and of how Wolf's research supports Westermarck.  Consequently, Frandsen fails to see how the evidence he presents is actually compatible with Westermarck's position (see Frandsen, 21-22, 25, 49, 73-74,  81-83, 85, 111, 115, 125-29, 136, 167).  In his 395 notes, Frandsen cites Westermarck three times and Wolf once (nn. 31, 33-34, 389).  But as far as I can tell, he hasn't actually read either Westermarck or Wolf.

Westermarck predicted that although the incest taboo is universal, the details of the taboo will vary across individuals and societies.  The taboo against sexual mating within the nuclear family (mating with one's parents, one's children, or one's siblings) will be universally strong, although some individuals will deviate from this either because of their temperament or their circumstances.  Although the Westermarck effect is a natural propensity, the fulfillment of that propensity requires social learning..  People will not necessarily show the Westermarck effect if they have not been reared from early infancy in close association with their nuclear family members.

Moreover, Westermarck's theory predicts that there will be great variation in the extension of the incest taboo beyond the nuclear family.  For example, whether the marriage of cousins, of uncles and nieces, and of in-laws is taboo varies according to the kinship systems and social circumstances of different societies.

Apparently, Frandsen's book challenges the core of Westermarck's theory by showing the wide acceptance of marriage between nuclear family relatives in ancient Egypt and Zoroastrian Persia.  He shows that while brother-sister marriages were extremely rare over the 3,000 years of Pharaonic Egypt, they became more common among the members of the Greek communities of Graeco-Roman Egypt (from around 300 BC).  He also shows that father-daughter, mother-son, and brother-sister marriages were justified as religious obligations for Zoroastrians during the Sasanian Period (224-651 AD) of Persia.

Frandsen fails to see, however, that all of the evidence he presents can be compatible with Westermarck's theory.  For example, he relies on the research of historian Keith Hopkins on the evidence for brother-sister marriages as being a common practice in Egypt (48-50).  But he does not notice that Arthur Wolf and Walter Scheider have shown that Hopkins' research fails to refute the Westermarck hypothesis.

The Westermarck effect arises when children are reared in their first few yeas with siblings and other family members.  Many of the sibling marriages in Hopkins' data are between siblings with considerable age differences, which suggests that they were not reared together in their earliest years, and consequently the inhibitions to sexual intercourse and reproduction would not have been acquired. 

Moreover, there is some evidence suggesting that some of the sibling marriages of people close in age were between people who could have been reared by wet nurses in their earliest years, and thus they might have imprinted on the body odor of their unrelated wet nurses, which would interfere with the Westermarck effect.

Another problem with the Hopkins data is that it does not give us any evidence of the success or failure of these sibling marriages.  Did such marriages produce high rates of divorce, adultery, and infertility?  If they did, then they would follow the pattern that Wolf saw with Chinese "minor" marriages--where parents adopted an infant girl, reared her with their son, and then forced the girl and boy to marry at puberty.

The same problems arise with the Persian evidence.  Frandsen gives us no evidence that these marriages of nuclear family members were successful.  In fact, he sometimes quotes remarks about such marriages being "difficult and hard" (73, 85).  But he doesn't reflect on what this means.  He also admits that there is little evidence as to how frequent these marriages were (81-82, 115).

Occasionally, Frandsen acknowledges Persian texts that seem to point to the many children of these marriages being born physically and mentally deformed.  But, again, he doesn't ponder the implications of this.

The evidence from ancient Egypt and Persian shows that a society can force brothers to marry their sisters, mothers to marry their sons, and fathers to marry their daughters.  But if these people have grown up in close association from an early age, Westermarck predicts that most of them will not be happy in their marriages.  And even if they are happy in their marriage, many of them will suffer the unhappy consequence of producing seriously deformed offspring.

This gives us the general pattern for an evolutionary moral psychology.  By nature, we are endowed with evolved propensities to learn certain moral emotions, like finding incest disgusting.  By custom, we learn the traditional norms of our society, but those social norms are constrained by our natural propensities.  By reason, we exercise individual judgment in deciding how best to live happy lives within the constraints of our natural desires and our customary traditions.

Larry Arnhart, "The Incest Taboo as Darwinian Natural Right," in Arthur Wolf and William Durham, eds., Inbreeding, Incest, and the Incest Taboo: The State of Knowledge at the Turn of the Century (Stanford, CA: Stanford University Press, 2004), 190-217.

Paul John Frandsen, Incestuous and Close-Kin Marriage in Ancient Egypt and Persia: An Examination of the Evidence (Copenhagen: Museum Tusculanum Press, 2009).

Walter Scheidel, "Ancient Egyptian Sibling Marriage and the Westermarck Effect," in Wolf and Durham, 93-108.

Arthur P. Wolf, Sexual Attraction and Childhood Association: A Chinese Brief for Edward Westermarck (Stanford, CA: Stanford University Press, 1995).


Anonymous said...

You might be interested to know that at Murdoch University, in Perth Western Australia....there's an institute that studies this kind of thing, and its pernicious secondary influence in the national policies of some nations & regions.

Their website is at

I'd highly advise viewing their global map of nations in which 1st cousin interbreeding (& closer) is very prevalent!

Larry Arnhart said...

That website is maintained by Alan Bittles. One summary of his research is "Genetic Aspects of Inbreeding and Incest" in Wolf and Durham, INBREEDING, INCEST, AND THE INCEST TABOO (2004).

A more recent summary is his paper coauthored with M. L. Black, "Consanguineous Marriage and Human Evolution," ANNUAL REVIEW OF ANTHROPOLOGY 39 (2010): 193-207. Here's the abstract:

"Mate choice among early human groups and in many historical populations was subject to both demographic and social constraints, ensuring that most unions were between couples who had coinherited substantial proportions of their genomes from common ancestors. Even in populations in which close consanguineous marriage was proscribed, community endogamy would have been sufficient to ensure high levels of homozygosity. Consanguineous marriage remains the choice of an estimated 10.4% of the global population, although there has been an overall decline in its popularity, especially in developed countries. Recent studies have indicated that the shift from consanguineous marriage to panmixia has been accompanied by a reduction in homozygosity. The concomitant predicted decrease in incidence of both recessive single-gene disorders and more common adult-onset diseases will have a significant impact on the health of future generations."

Anonymous said...

He also doesn't show that those forced into these marriages didn't still feel disgust and only did it out of social pressure.

Larry Arnhart said...

Yes, you're right.

Bittles supports Westermarck's theory of the incest taboo.