acts of bravery can’t follow a chimp home from the battlefield any more than acts of cowardice. Without language, courage just becomes suicidal foolishness. But once our ancestors escaped the eternal present by learning to speak, they could repeat stories that would make individuals accountable for their actions—or rewarded for them. That would create a strong incentive not to turn and flee while others fought off the enemy. Better to fight and die than to face ostracism and contempt back home.
