David Brown in today's Washington Post: "Why do we help out our relatives when one of them needs a buck or a meal, and who gains the most from such acts of generosity?
It's a tough question to answer in human populations, where self-awareness and cultural expectation cloud the biological forces that underlie behavior. But there are hints of answers in other species.
Two studies of birds published this week report surprising insights into the evolution of altruistic behavior.
One study suggests that sometimes the greatest beneficiaries are neither those giving or receiving alms but those whose main job is the care and feeding of the neediest members of the population.
The second study provides evidence that living in unpredictable conditions is a big motivator for mutual assistance, that a kind of "we're all in it together here in the Jamestown Colony" consciousness drives selfless behavior..."
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It sounds like self-interest trumps cooperation among birds, particularly in drought years, but biologically the brother-birds who engage in this helping behavior are promoting their own strand of genes, so it makes sense from a biological perspective.