Stretch Genes

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H. Allen Orr reviews Nicholas Wade's A Troublesome Inheritance: Genes, Race and Human History, in the NYRB:

Wade’s main claim is that human races likely differ in social behavior for genetic reasons as a result of recent evolution. These slight differences in behavior may, in turn, explain why different sorts of social institutions appear among different peoples:

Institutions are not just sets of arbitrary rules. Rather, they grow out of instinctual social behaviors, such as the propensity to trust others, to follow rules and punish those who don’t, to engage in reciprocity and trade, or to take up arms against neighboring groups. Because these behaviors vary slightly from one society to the next as the result of evolutionary pressures, so too may the institutions that depend on them.

Evolutionary biology might therefore have something to say about why some peoples live in modern states and others in tribal societies, and why some nations are wealthy while others remain mired in poverty.

The science in A Troublesome Inheritance is mostly inspired by the genomics revolution of the last decade or so. (A genome is the full complement of DNA, the hereditary material, that an individual carries.) This revolution has been, to a considerable extent, a technological and economic one. The high-tech approaches needed to “sequence” a person’s genome—to decipher the three billion units ofDNA that make up a human genome—is now sufficiently automated and inexpensive that geneticists have sequenced the genomes of thousands of people from around the world. In the course of this work, results have emerged that throw light on racial differences. Geneticists, Wade says, have been reluctant to talk openly about these results, which are sometimes politically sensitive. He takes up this task here.

A Troublesome Inheritance cleaves neatly into two parts. The first is a review of what recent studies of the genome reveal about our evolution, including the emergence of racial differences. The second part considers the part that genetic differences among races may play in behavior and in the social institutions embraced by various races. These two parts fare very differently.

More here.