Prehistoric tribe of men, pregnant women and children were bound and battered by invading rivals 10,000 years ago http://www.dailymail.co.uk/sciencetech/article-3408654/Is-mankind-s-massacre-Prehistoric-tribe-men-children-pregnant-women-bound-battered-stabbed-death-invading-rivals.html
AGGRESSION S APPEARS TO BE HARD-WIRED INTO THE HUMAN SPECIES