Sociality, like multicellularity, has appeared numerous times, in diverse taxa, and reached many different levels of integration. ~ American zoologist James Hunt
Game theory mathematically demonstrates that cooperation helps both the individual involved and the group. It also shows that cheaters cannot prosper in a group where reputations become established. Even bacteria remember who their friends are.
From an evolutionary perspective, eukaryotes are an ipso facto triumph of cooperation. Even unicellular organisms have sophisticated ways of working together.
Single-celled algae may commit suicide if it might help the population in which it lives. This not only benefits others of its kind, but also has an inhibitory effect on the growth of competitive species.
The mental acuity of plants is beyond ken. Though they compete and are shrewd calculators of fairness, they also cooperate and practice generosity.
Many animals, inherently emotional, have an aptitude toward altruism, however seldom it finds expression in those who lead largely asocial lives. This inclination is even more integral in social animals, and especially those with parental care. Inclusive fitness would be nothing but an empty hypothesis if there were no payoff to the creature performing it.
Affinitive behaviors create their own emotional reward. It feels good to help, in the same way that it feels good to have one’s existence appreciated, and to appreciate another. Humans are simply selfsame to other animals in this regard.
Once calculation of cost enters the picture, cooperation becomes the dicey proposition that confounded Darwin and other evolutionary biologists. At that point, the tortured calculations of reciprocity must be grappled with. Limiting altruism to this calculation is unrealistic.
Reciprocity is merely a check for fairness. Without the spark of self-reward for kindness built-in, the calculus of cooperation could never compute in the way that it does in real life.
Generous behaviour is costly, as it involves the investment of one’s own resources for the benefit of others. Nevertheless, generous behaviour is common. Generous behaviour is known to increase happiness, which thereby motivates generosity. ~ Korean cognitive psychologist Soyoung Park et al