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The Synergy of Cooperation Cooperation occurs when two or more individuals behave in a coordinated fashion to the gain of the parti– cipants.

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Nature is replete with cooperating individuals, both members of the same and of different species.

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Ants defend aphids, who provide them with sweet droplets of honeydew from their rear ends.

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Cleaner fish pluck parasites from predatory fish that could swallow them in an instant, but do not do so because a colleague is better than a cutthroat.

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Juvenile birds remain at the nest to help in the rearing of their parents’ subsequent broods.

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How selfish genes translate into unselfish organisms has been a central question of modern biology.

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In the “survival of the fittest” view of the world, individuals are merely gene–making machines, and every behavior is ultimately in the individual’s self–interest.

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Scientists have developed two widely accepted explanations for the cooperative and selfless behavior commonly shown by animals (human included).

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The first theory, known as kin selection, was set forth in a 1964 paper by British evolutionary biologist William Hamilton.

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By helping close genetic relatives, one is indirectly investing in one’s own genes.

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The most prominent example is the care and pro– tection of young.

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Many studies have shown that individuals will sacrifice immediate selfinterests to benefit close relatives.

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But there are myriad examples of animals acting compassionately toward others who are not kin — in some cases they are not even of the same species.

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That’s where the second theory, reciprocal altruism, comes in.

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Devel– oped by the American evolutionary biologist Robert Trivers in 1971, reciprocal altruism refers to the exchange of a favor now for the prospects of a returned favor later.

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Readers should note that reciprocal altruism depends on individuals’ ⒜ doing favors to one another, ⒝ remembering the favor later on, and ⒞ recognizing the individual who did the favor.

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Reciprocal altruists have minds, and feelings.