Altruism: would you risk your life for a stranger?

What actually is altruism? Lewis Thomson tells of one remarkable example of this behaviour...

On the 2nd January, 2007, construction worker Wesley Autrey was standing on a subway platform waiting with his two daughters for the train to arrive. Beside them a young man began to have a seizure and fell onto the tracks with a train fast approaching. Autrey realising there wasn’t enough time to pull him up jumped down onto the tracks and lay on top of the man pinning him to the ground to stop him flailing. Amazingly, the train passed over them missing Autrey by just an inch.

This is just one of many examples of instances when an individual has risked their own life to save someone else. And although this may seem like a very human thing to do, altruism - sacrificing something of yours for the good of another individual - is a behaviour found in many species. Individuals will give up their food, breeding rights, even lives to help others survive.

But if evolution is all about the survival of the fittest, how do behaviours like this evolve?

Music: Bensound, drum sfx: Bensound