Electrolite posts extracts from a Louis Menand review of Pinker’s Blank Slate. I’ll do the same with yet another extract from my own draft review. Comments most welcome:

The ‘evolutionary psychology’ model put forward by Pinker is essentially a rebadging of the human sociobiology model launched with great fanfare in the 1970s. The basic innovation in sociobiology, as opposed to earlier Darwinian models of society, was a central focus on reproductive strategies, rather than on adaptations associated with the struggle for food and survival. Since sex and reproduction are central human concerns at all times, the application of sociobiological analysis to humans promised to find a genetic basis for central institutions of society such as marriage and the family.

Moreover, a focus on reproduction implies a focus on genes rather than organisms. The ‘interest’ of genes in reproducing themselves does not coincide with any obvious notion of the interests of organisms. Moreover, the ‘genes-eye’ view focuses attention on conflicts of interest between mates, between sibling and, most strikingly, between mothers and children. Using this perspective, sociobiologists promised to resolve many long-standing controversies about family structure, sex roles and so on.
There were some obvious difficulties with this enterprise. Unlike other animals, human societies display a bewildering variety of familial and social arrangements. Moreover, most humans see themselves as conscious agents pursuing a wide range of goals, of which reproduction is commonly not the most significant. Most saliently, there is the widespread occurrence of homosexuality and celibacy, behaviors not apparently conducive to the dissemination of one’s genes.

A further difficulty was that, unlike with other animals, there was no satisfactory empirical data on which to base the model. If sociobiology is correct, human behavior today reflects optimal reproductive strategies in the prehistoric societies of the African savannah. But those societies are long extinct, leaving little behind from which to make inferences about the selection pressures they faced.

Hence, it is necessary to rely on observations of the cultural organisation of the hunter-gatherer bands that survived to the modern era, invariably in marginal environments that were slow to attract the attention of those with more advanced technology. Anthropologists rarely reach such bands before their traditional organisation has commenced radical change as a result of earlier contact with the advance parties of Western civilisation and the goods and diseases that accompany them.

In the first flush of enthusiasm, the advocates of human sociobiology promised that these difficulties would be overcome. Homosexuality and celibacy were to be explained by hypothetical ‘helper’ genes, which reproduced themselves by assisting the reproductive success of family members.

Pinker sees this enterprise as having been highly successful, and certainly some of the more extreme critics look silly today. Nevertheless, there is a striking difference between the confident claims of human sociobiology and the relatively modest offerings of evolutionary sociobiology. On homosexuality, Pinker frankly concedes that we have no idea why some people are homosexual and others are not.

Similarly, with regard to the heritability of behavioral traits, Pinker suggests that about 50 per cent of the observed variation in individual character traits within modern societies is genetically determined. (This proportion is conditional on the amount of variation in environment for the population being considered, and would be much lower for comparisons between societies.) Pinker views this as a triumph over nurturists like Leon Kamin who asserted in the 1970s that there was no evidence to justify a non-zero estimate for heritability (not the same thing as saying the heritability is equal to zero). Pinker does not mention the fact that, at the same time, leading naturists like Eysenck and Jensen were claiming 80 per cent heritability, and makes Kamin look silly by not mentioning his main point, which was to show that the twin studies of Sir Cyril Burt, on which Eysenck and others relied relied, were almost entirely fraudulent, being based on fabricated data collected by non-existent collaborators.