I used to teach philosophy of biology, and one of the things we would cover are the standards of evidence in evolutionary biology. Some critics of Adaptationist models charge that these scientists' main criteria for the soundness of a theory to explain the evolution of a species is that they can come up with some "plausible story" about why that species' ancestors were more fit than their competitors.

If the "plausible story" criterion is indeed the way they judge acceptable theories, they open themselves up to all sorts of speculation, biases, etc, especially when the traits they are talking about are behavioral (as opposed to strictly physiological).