I cannot stress this enough; you cannot determine evolutionar basises for behavior.

Why though, isn't that something you can generally do for other species?

Evopsych is fundamentally rectionary because it’s entire goal is to create justification for the current state of affairs by asserting that they are the result of biological and evolutionary processes.

This is true in regards to the general practice of "Evolutionary Psychology" as a field of human social theory though, true.