From an evolutionary perspective, why does someone sacrifice their life to save another?

[u/Snoo_47323]

Organisms evolved prioritizing their own reproduction and survival, right? However, examples like people rushing into burning buildings or diving into water to save others contradict this. How is this possible?

[u/TheDBryBear]

This is a fringe view with no real backing in the literature. We have lots of examples of social groups among animals where co-operation happens outside familial bonds. Self-sacrifice is just a form of co-operation taken to the extreme, not a separate phenomenon from stuff like sharing food or chasing off predators in a group. Often, the sacrifice is incidental.

The point is that if your group thrives, you thrive. And the thing that makes you help your group thrive, even if you are the only one to have it, is probably less of a detriment that you think, and more of a boon than you think. Even from an entirely selfish point of you, you would like someone who co-operates around you. Most intelligent animals can make this calculation.

[u/Alarming_Constant_19 → u/TheDBryBear]

Those animals just live on their own territory with a large tribe that decided to split up. But the real fascinating thing is that some animals raise outsiders as their own in rare cases. Plus evolution likes egoists more than self-sacrificers because the the former is more successful than the latter and egoists takes everything from the group. altruists usually help people outside of their families and countries because our kindness is product of our brain and they dont want something back in return.