Some clues :
Douglas P. Fry : Pacified Past
Azar Gat : Warfare as an Ancient Feature
Robert Carneiro : Complexity and State Formation
Was the 20th century one of the most violent in human history ? (with two world wars and numerous other conflicts) ?
i also like the documentary series : “The Ascent of man” from the BBC in 1973 by Jacob Bronowski.
I’ve read that abortion is consistently used to eradicate female human lives ( men will murder daughters in order to have a son ), & of course in India men murder their wives, too ( a census some years ago recorded that there weren’t 30,000,000 women who should have been there )…
China is big on eradicating daughters for sake of sons ( the 1-child-per-family era was famous for this ).
I’ve read that the single most-reliable predictor of war, is too-many-males for balance to be possible with females.
Connect the dots.
I’d like to see some sources. Where did you read that, Facebook?