THE COMPARATIVE APPROACH AND HUMAN SOCIOBIOLOGY 195 approach. When one makes comparisons between species in different environments, the observed differences in behavior can generally be assumed with some confidence to have a genetic basis. However, when one is making intraspecies comparisons across different environment in humans, it is not so clear that these differences represent genetic differences.
In sociobiology there seems to be two dominant view on this issue. Some sociobiologists (Wilson, 1978; Rushton, 1985) assume that much of the phenotypic variation in human behavior can be attributed to individual and group genotypic difference. Others argue, as Richard Alexander does (Alexander, 1979; 1987), that the human ability to behave adaptively in different cultural and environmental contexts is not the result of cross-cultural or individual genetic variation, but rather comes from our tremendous capacity to learn about our environments. According to this view, the capacity to learn has itself evolved by natural selection and is therefore not undifferentiated and generalized, but is constrained in a fashion such that humans will frequently be able to select between alternative strategies and behaviors in a fashion that maximizes fitness. We all are endowed with what might be called a "general fitness calculator." The general fitness calculator assures that we behave, in most instances, in a fitness enhancing fashion. While individuals may vary behaviorally in terms of their abilities to calculate which actions most enhance fitness, the ability to make these calculations does not necessarily rest on genetic differences, but may as well be based on differences in social learning and experience.
In conclusion, the point I think important to emphasize is that regardless of whether one believes that behavioral differences have a genetic basis or not, (and I agree with Clutton-Brock and Harvey (1979) that the term "adaptation" should not be limited to differences with a known genetic basis) adaptations can be recognized by their effects on fitness. The fitness value of every behavior and behavioral strategy is situation dependent. This reality means that different behaviors will be more commonly associated with some specific environmental contexts than others. Such correlations lead us to believe the behavior functions as an adaptation. The only difference between a situation in which variation is largely the result of genetic difference and the situation in which it is not is that correlations between specific forms of behavior and specific environments are likely to be stronger in those instances in which genetic factors contribute strongly to differences in the phenotypic expression of traits.