There are large effects on behavior of psychopathy, people that are affected by a psychopath will mostly -- at a minimum -- make a point of warning everyone else they know. That is very detrimental for the psychopath. (Note that how we communicate really applies evolutionary pressure. Just check the number of muscles in a human face compared to most anything else. This is not a small effect.)

Also, psychopathy seems to be partly environmental and partly from genetics. And exist in most populations.

All this suggests an evolved behavioral strategy.

Researchers need to check for your hypothesis (the large different effects almost cancels each others out in many types of historic societies(!), so it is just a random genetic drift) since afaik it is a standard hypothesis, but it does seem very unlikely.