Frankly many pre-modern, pre-civilizarion humans were assholes. Read many studies or accounts of life in relatively isolated tribal societies and hair curlingy awful accounts of violent and sometimes institutionalised abuse are uncomfortably common. Leave the safety catches off basic human urges for long and it can get pretty ugly.
Yes, I know, it's just completely insane to declare that we've somehow qualitatively moved past our brutish origins as long as torture, rape, and murder remain de facto extensions to politics.
I have no reason to doubt that quantitatively we have made some progress - although Pinker's arguments are most definitely not universally accepted in the scientific community.
