I wouldn't have assigned much of a prior probability to either of those common sociobiological beliefs, myself. It would hardly surprise me if they were both complete nonsense.

So what do you mean when you say that these beliefs are "standard" or "widely held?" Obviously, I am not a representative sample of the population, so I may have no opinion on a widely held belief. But I'm not aware of strong evidence that these beliefs are widely held, or at any rate are more widely held than the evidence would warrant.

Or, with tongue firmly in cheek, I claim that I'm presenting counterevidence for the common belief that [insert proposition here] is a common belief...