In this article, arguments forwarded by sociobiologists to account for key features of human individual and social development are examined, and the logical and empirical bases of the evidence marshalled in support of these arguments are evaluated. Based on a genetic reductionistic and determinist account of human development, sociobiologists propose (a) that humans are impelled across their lives to aggressively enhance the inclusive fitness of their genotypes, and (b) that male and female genotypes differ in their gametic potential. These sex differences are predicted to result in gender differences in sexual and social behavior and development, as well as differences in the functioning of men and women in social institutions (such as the family) involving, in particular, child-rearing. Three lines of research are drawn on to support these ideas. These involve (a) interspecies comparisons and the concept of homology; (b) estimates of the heritability of human behaviors, and (c) the view that the evolution of human behavior invariably involves adaptation. Logical and empirical problems can be identified with each line of work. As a consequence, extant sociobiological ideas are of little use in accounting either for general features of human development or for the nature or presence of individual differences. A developmental contextual perspective is proposed as a scientifically viable alternative to the genetic determinism and reductionism of sociobiology.