At the very least, it was beneficial to have a larger share of those people around.

Undisciplined

True.  Being an aggressive and violent asshole was probably socially adaptive for a long time, when there were plenty of outsiders to whom your urges could be directed.  The Iliad is a nice account of some of that.  

Now all they have is cryptotwitter.

elvismercury

Meta Econ Takeover Day 16

It's not just about smarter. This modern environment is so novel that a whole host of traits that were highly adaptive 10,000 years ago are now maladaptive.