Although sociobiology (SB) and evolutionary psychology (EP) are not competitor projects, they must be integrated, argues Driscoll: according to her both psychological mechanisms and behaviors represent kinds of adaptation. In order to achieve an integrate theory, she focuses her discussion on an Sterelny & Griffiths’ idea (Sterelny 1992; Sterelny & Griffiths 1999), for whom SB’s attempt to identify evolutionary explanation for discrete units of human behavior is substantially wrong. Since the relation between psychological mechanisms and produced behaviors is one-to-many, each behavioral change (e.g., B1) cannot exist without a relative change in the mechanism that produced it, which then produces other behaviors’ changes (B2, B3…). Therefore, none behavior is supposed to evolve independently of others, thus it cannot be an adaptation. According to Driscoll’s analysis, there are mainly two objections to this reasoning. First of all, this argument relies on a too strong interpretation of Lewontin’s quasi-independence criterion (QIC). On the contrary, there should be at least one way to change T-trait such that the positive contribution to an organism’s fitness is greater than the total negative contribution supplied by any connected trait: in this way a trait can be considered under natural selection. The latter is that merely possession of a mechanism supporting different behaviors does not imply that changes in one behavior make necessary changes in others. Otherwise, an identical mechanism should manage different inputs in order to produce as many different outputs as it is possible. Seems to me that both these objections are unsatisfactory: as a matter of fact, Driscoll’s interpretation of QIC (Brosnan 2009) does not solve the mereology problem about how legitimately identifying behavioral units; the second objection, relying on a strong computational model of human psychology, can be theoretically assumed but not empirically supported.
Brosnan, K. (2009), Quasi-independence, fitness, and advantageousness, Studies in History and Philosophy of Biological and Biomedical Sciences, 40, 228–234 http://www.sciencedirect.com/science/article/pii/S1369848609000351
Driscoll, C. (2004), Can behaviors be adaptations?, Philosophy of Science, 71, 16–35. http://www.jstor.org/discover/10.1086/381410?uid=3738296&uid=2134&uid=2&uid=70&uid=4&sid=21101593659077
Sterelny, K. (1992), Evolutionary explanations of human behavior, Australian Journal of Philosophy, 70 (2), 156–172. http://www.tandfonline.com/doi/abs/10.1080/00048409212345051
Sterelny, K. & Griffiths, P. (1999), Sex and death, Chicago: University of Chicago Press. http://www.amazon.co.uk/Sex-Death-Introduction-Philosophy-Foundations/dp/0226773043