He who was ready to sacrifice his life, as many a savage has been, rather than betray his comrades, would often leave no offspring to inherit his noble nature.
This form of altruism is really a form of delayed gratification because ultimately the altruist will personally benefit, but only after some time has passed.
If amygdala dysfunction robs people of both empathy and the ability to recognize fear, could amygdala-based sensitivity to others’ fear be a critical ingredient for altruism — including acts of extraordinary altruism like the one that saved my life?