Altruistic behaviour is difficult to understand and its evolution has proven to be interesting as the reason for behavioural changes cannot completely be defined. Additionally pure altruism is rarely found in nature, as those noble animals tend to die before they can pass down their genetic traits. Though Darwin did not completely understand altruism his work, the Descent of Man, is one of the first scientific published works that describes altruistic behaviour.
His observation of animals helping others actually opposes his evolutionary theory of the survival of the fittest because in order for an individual to survive they need to take care of themselves and not sacrifice for others. According to natural selection theory, benevolent behavior should not evolve because it, technically, costs or even harms the doer’s fitness. Darwin did attempt to explain this phenomena by including it in group selection, as in order for groups to survive natural selection may actually favour groups of individuals and in this case the altruistic behaviours would be passed down to the next generation.
(Darwin, 1871). This phenomenon of cooperation was not completely described until Kropotkin published a book, a collection of essays, dealing with mutual aid (Kropotkin, 1902). This work was a direct response to social Darwinism. Kropotkin was able to build a more satisfactory tie to individual natural selection and cooperation, displaying that mutual aid selection directly benefits individuals own struggle for personal success, so that cooperation between species will actually be the best path for individual success (mutual aid, 1955).
Altruistic behaviour has since been researched and discussed by many scientists since its recognition in evolutionary biology. Scientists have thought that altruistic behaviour may be instinctual and that helping behaviour survives because it makes the individual feel good, particularly in humans (Wilkinson, 1988). There is also the theory that if an animal helps another then they may have the favour repaid back in the future, which can be found in human society (Kreb, 1952).
Much research delving into altruistic behaviour and evolutionary biology cannot find a firm fit for altruism in general evolutionary terms. Inclusive selection or kin selection, in which species display behaviour that selections for those in their family to reproduce, cannot completely explain altruism as it does not attempt to explain why differing species help each other (Hamilton, 1964). Symbiotic relationships, in which both species benefit, are based on specific conditions such as long-lives, dependence for food, performing a necessary service etc.
(Trivers, 1971). In symbiotic relationships the help is eventually repaid by the species even if it takes a long time as the species my loss a little fitness at the current time but in the end the long term benefit will far outweigh any previous problems or disadvantages, known as reciprocal altruism. Much work has been done to investigate reciprocal altruism and inclusive fitness, particularly as evolutionary biology has evolved to include theories such as the game theory and predictive behaviour.
Game theory points out that reciprocal altruism can also include negative behaviour, such as a cheater can expect to be punished in the future for its behaviour to others. (Trivers, 1971) It has been argued that these two types of behaviour, inclusive selection and reciprocal altruism are not truly altruism, as with altruism the species providing help does not get anything in return; much of research is devoted to study these evolutionary ideas (Rothstein and Pierotti, 1980). In the 1980s altruistic behaviour began to be investigated in Primates particularly with grooming behaviour.
Primatologists noted that an individual’s status in a hierarchy seemed to be related to their relationships with others. Aiding dominant members seemed to be favoured. Juveniles needed to ingratiate themselves in the group and aiding a dominant female is a means of securing status in the hierarchical society of bonobos. (de Waal, 1989) Certain primates will chose to groom other primates and later they will gain some sort of benefit. A more recent study has shown a different aspect of reciprocal altruism as dominant female primates were found to groom subordinate primates, a type of grooming-down which had not been observed yet (Parr, et al.
1995). Current altruism research is based around game theory and includes behavioural manipulation, bounded rationality, conscience, kin selection, memes, mutual aid, selective investment theory, sexual selection, reciprocity, and pseudo-reciprocity. The Price equation was developed to redefine Hamilton’s work on kin selection and describes natural selection and evolution. In this mathematical equation altruism is defined as a behavioural genetic predisposition that increases the fitness of the group which in turn causes the individual that belongs to that group to benefit.
(Frank, 1997). A fantastic example of this is with slime mould. Slime mould live as individuals until they are starving when the aggregate and form a multicellular organism and some cells sacrifice themselves for the benefit of the group. Altruism in humans has begun to be investigated and shown that specific regions of the brain will trigger charitable or helping behaviour. It was found that altruism does not suppress selfishness but actually very basic to brain function and triggers a pleasurable response (Moll and Grafman, 2006).
The theory of group selection has re-emerged when looking at aboriginal lifestyle in Africa. Individuals of groups were found to be more closely related then previously believe suggesting that the nicest really do survive. Those that shared food and other goods would reproduce and pass on their genes as individuals would ban together during difficult times (Fischer, 2006). Interestingly it is through religion that altruism is spread throughout the human population. Buddhism, Judaism, Sikhism, Christianity, Islam and Hinduism all place particular importance on altruism.
There are many individuals that oppose altruism saying that it is a morality, more of an ethics branch than evolution, as individuals do not need to be altruistic to survive. Though as social beings an altruistic natural may make you more social it will not ultimately cause your death or the inability to pass on your genetics. Most of the controversy with altruism today revolves around the factor that altruism may not apply to humans, though humans do have symbiotic relationships with other species, (think of the bacteria in your digestive tract).
There is a split between real altruism and psychological altruism though most will agree that those individuals that care for others, such as parents for their children will be able to survive in society much easier than those that do not care for anyone. Most of altruism in humans is psychological and not due to a selfish gene. Also due to advances in technology ands science natural selection has taken a bit of a turn or slowed down so understanding altruism in humans is possible quite different then observing altruism in other species. References;
Darwin, C. (1871). The Descent of Man and Selection in Relation to Sex, New York: Appleton Fischer, R. , (2006), "Why altruism paid off for our ancestors" (NewScientist. com news service) Frank, S. A. , (1997), The Price Equation, Fisher's Fundamental Theorem, Kin Selection, and Causal Analysis, Evolution 51 (6): 1712–1729 Hamilton, W. (1964). The genetical evolution of social behavior. J. Theor. Biol. 7 I: 1–16. Moll and Grafman, (2006), Human fronto–mesolimbic networks guide decisions about charitable donation, PNAS, 103 (42);15623-15628
Parr, L. , Matheson, M. , Bernstein, I. & de Waal, F. (1996). Grooming down the hierarchy: allogrooming in captive brown capuchin monkeys, Cebus paella. Rothstein, S. & Pierotti, R. (1980). Reciprocal altruism and kin selection are not clearly separable phenomena. Journal of theoretical biology, 87(2), 255-261. Trivers, R. (1971). ‘The Evolution of Reciprocal Altruism’, Quarterly Review of Biology, 46: 35-57. Wilkinson, G. (1988). Reciprocal altruism in bats and other mammals. Ethology and sociobiology, 9(2), 85-100.