DNA and Destiny

In a useful, opinionated, accessible survey of the nature-versus-nurture controversy, Steen, a Tennessee medical researcher in brain physiology, argues that human behavior is roughly half the result of genes and half the result of the environment, with an ongoing interplay between the two forces. He reviews recent research suggesting that children structure their own environments, selecting milieus congruent with heritable personality traits and proclivities. Steen defends intelligence tests as a measure of general problem-solving ability, but he attacks Richard Herrnstein's and Charles Murray's bestseller The Bell Curve as a pseudoscientific legitimization of racism. He finds the evidence of a genetic and hormonal basis for homosexuality to be fairly compelling. Alcoholism, he maintains, is a disease to which many people inherit a genetic susceptibility, although family environment plays a strong causative role. His synthesis touches on many topics, from cognitive and emotional differences between men and women to transsexuality, eugenics, sociobiology and a reported link between attention deficit-hyperactivity disorder and criminality. (May)