16. 脑容量
P1:脑容量减少,脑容量和身体体型的比例没变
Average volume of human(-) --> human body mass (-)
ratio of brain volume to body mass : ex human = human
P2:脑容量减少得更快 给出解释 质疑给出的解释
But:brain volume shrank faster
genetic mutation --> brain development --> human cognition
survival demand agricultural < hunter gatherer) --> reduce size
But: shrinkage occurred among all humans all societies.
P3:更有理有据的解释
our human ancestors domesticated themselves
--> less aggressvie individuals --> fewer conflicts --> improve reproductive--> like modern human
--> simple genetic changes --> rentention juvenile features.