I've just sent off my chapter "Real Behaviorists Don't Wear Furs" for Nandita and Vartan's book Animals in Human Signification or something like that, and I have two little chunks of argument that emerged this morning pursuant to that, I'll split them into two posts, this one and the next.
There is a mistake, I think, in the premise of evolutionary psychology. According to a strong version of this view, adaptationist explanations of behavior (explanations that appeal to the fitness-conferring value of various behaviors) replace intentional explanations (explanations that take intentional states to be causal, as in, "He went to the river because he wanted some water"). (Let me note in passing that to whatever degree evolutionary psychology is a valid way to explain behavior, it is equally valid when applied to humans as when applied to other species; the evolutionary psychologist has no grounds for claiming that humans have "minds" while other species do not. But that is not my point today.) The mistake here is to confuse the "why" with the "how." We are in need of various explanations. One thing that needs to be explained is why the organism behaves the way it does. Adaptationist explanations may serve to satisfy that explanatory need. But how the organism manages to achieve the behavior is a different explanandum entirely.
Here's the little bit of argument that came to me this morning: An adaptationist explanation might explain how a tiger came to have a sharp claw. That doesn't mean that the sharpness of the claw itself is no longer of interest to a zoologist. The sharpness must be referenced if we are to understand how the tiger satisfies its nutritional requirements. It is an indispensable part of the "how" explanation.
Adaptationist explanations, as "why" explanations, lie "upstream" from "how" explanations. As Aristotle pointed out long ago, there are in fact various types of causal explanation. No one would think that the claw's sharpness was causally irrelevant to the tiger's functioning. But evolutionary psychologists (Dawkins) make the same mistake when they suggest that the intentional properties of psychological traits are causally irrelevant on the grounds that the real cause is genetic replication. Thus to explain that the dog is adapted to love you doesn't constitute any kind of argument that the dog doesn't really love you. (Same as in the infant's case.)