They were evolved for a world in which people lived in very small groups, rarely met anybody who was terribly different from themselves, had rather short lives in which there were few choices and the highest priority was to eat and mate today.
在大脑为之进化的世界里， 人类生活在很小的群体当中， 周围都是和自己一样的人， 人们的寿命非常短， 选择也非常少， 最重要的事情就是 “今朝有酒今朝醉”。