LINK: ‘There is no such thing as a truly selfless act’

Reciprocal altruism is a model wherein animals help unrelated
individuals and accept a short-term loss if it means a long-term gain.
So if a starving bat is helped by a well-fed one, the action is done
because of some deep, unconscious instinct that in the future the tables
might be turned: today’s starving bat might be tomorrow’s well-fed one.