Because the human body develops into maturity over ~18 years. It probably doesn't really take that long to teach people to cooperate, but if we pulled children from a social learning environment earlier they might overwrite that societal training with something they learn afterward.
Because the human body develops into maturity over ~18 years. It probably doesn't really take that long to teach people to cooperate, but if we pulled children from a social learning environment earlier they might overwrite that societal training with something they learn afterward.