Since the first declarations of sociobiology, Wilson has produced the long book and then the short; this is the short form, with some new twists, of Genes, Mind, and Culture (1981), which Wilson also wrote with his younger Harvard colleague, physicist Lumsden. Their ideas, spelled out in neologisms like ""culturgens"" and ""epigenesis,"" are that mind (and human nature) are the result of the co-evolution of genes and culture. Mental development is constrained by certain epigenetic rules, genetically-set physiological bounds, that (for example) limit the colors we perceive, determine our language potential, and incline us toward certain kinds of fears or behaviors. A culturgen is a specific example--like a bias toward incest avoidance--that predominates in all cultures presumably because it is based on an epigenetic rule that reflects principles of natural selection. Genes thus influence culture, but not as a one-way street. Culture in turn effects genetic change (in as little as a thousand years, Lumsden and Wilson aver) by favoring certain behaviors that subsequently lead to a greater distribution of genes associated with those behaviors. Thus far sociobiology's venture into brain science and anthropology is a plausible exercise in interactionist theory. Subtle dictates crop up, however. We are told that genes prescribe ""the most efficient"" epigenetic rules so that human populations evolve toward forms of learned behavior that confer the greatest survival and reproductive power. ""Most efficient"" by what criteria? And how explain today's worldwide dilemmas? The sociobiologists seem to be postulating a 19th-century Comptean positivism. Their attempt to mathematicize the development of mind is shored up by the arbitrary assignments of probabilities to those hoary favorites, the incest taboo and the practices of remanent hunter-gatherer societies. Lumsden and Wilson have come to grips with exciting questions like the relationship of mind to culture, of culture to genes and the uniqueness of mankind. Their musings are provocative and the writing is often stylish (compared with the heavy-handed and equation-peppered earlier tome). But much as they try to establish a scientific rigor, their answers remain philosophical and speculative.