Come back with your shield - or on it.

Our kind might not be able to cooperate, but the Spartans certainly could. The Spartans were masters of hoplite phalanx warfare where often every individual would have been better off running away but collectively everyone was better off if none ran away than if all did. The above quote is what Plutarch says Spartan mothers would tell their sons before battle. (Because shields were heavy if you were going to run away you would drop it, and coming back on your shield meant you were dead.) Spreading memes to overcome collective action problems is civilization level rational.