 He is co-author of the book "The 10,000 Year Explosion".In opposition to what he sees as the conventional wisdom that civilization has been a static environment which imposed stabilizing selection on humans, Cochran, along with like-minded anthropologists such as John D. Hawks, contends that haplotype and other data indicate the selection of genes has been strongest since the advent of farming and civilization.Cochran and co-authors Jason Hardy and Henry Harpending suggest that the high average IQ of Ashkenazi Jews may be attributed to natural selection for intelligence during the Middle Ages and a low rate of genetic inflow.