 Another problem for behavioral ecology and sociobiology is their focus on trying to understand the biological basis of behavior as such. The behavioral focus made sense to those behavioral ecologists influenced by Lorenz and Tinbergen’s ethology, but once cognitive psychologists became interested in applying evolutionary thinking to their work, the effects of the cognitive revolution in psychology began to have an effect on some of the “sociobiological” thinkers, and they transformed sociobiology into evolutionary psychology (Cosmides and Tooby, 1987; Tooby and Cosmides, 1990). The result of the cognitive revolution in psychology was that many psychologists came to regard the proper target of explanation in psychology to be genuinely psychological states or mechanisms rather than behavioral dispositions (as in Skinnerian Behaviorism) (Chomsky, 1959). In cognitive science since the middle of the twentieth century, psychological states and mechanisms have largely been understood in computational and materialist terms, that is, that the mind is the brain, and that brain states and mechanisms are essentially computational states and computers respectively (though almost certainly not serial computers). Psychological descriptions, then, are simply descriptions of these brain systems in computational or information-processing terms; generally they appeal to representations, decision rules and algorithms that brain systems process. The shift in methodology and theory represented by this change in approach was extremely significant. But it also appears to have made cognitive psychologists interested in evolution averse to thinking of behavioral dispositions as proper targets of evolutionary explanation, just as they were averse to thinking of them as the proper targets of psychological explanation (Cosmides and Tooby, 1987). This issue never seems to have arisen for the human behavioral ecologists; indeed, not only is behavior treated as the only proper target of evolutionary explanation, but psychology is explicitly ignored in favor of behavior for methodological reasons—the focus on behavior is part of the “phenotypic gambit” (Grafen, 1984) which (as described above) simplifies evolutionary modeling and the process of deriving explanations from it in human behavioral ecology.