Bite Sized Science: Nice Genes
By Keir Liddle
Altruistic or pro-social behaviour has long been of great interest to psychologists, with many competing explanations offered to explain the phenomenon. Increasingly, it has been suggested that pro-social behaviour can be explained in evolutionary and genetic terms.
From the study of animal behaviour and social evolution, it has been suggested that altruism refers to behaviour by an individual that increases the fitness of another while decreasing their own; doing good for no reward, perhaps at your own expense. The concept, sometimes referred to as “survival of the nicest”, was first proposed by the Russian zoologist and anarchist Peter Kropotkin in his 1902 book, Mutual Aid: A Factor of Evolution.
Two related strands of research on altruism have emerged out of traditional evolutionary analyses, and from game theory, respectively: Axelrod’s Evolution of Cooperation being one well known example.
Some of the proposed mechanisms for altruism are:
- Reciprocal altruism
- Selective investment theory- a theoretical proposal for the evolution of long-term, high-cost altruism
- Sexual selection; in particular, the Handicap principle
Twin research carried out by Gary Lewis and Timothy Bates at the University of Edinburgh’s Department of Psychology has strengthened the case for a genetic component in pro-social behaviour. The scientists analysed data from nearly 1000 sets of twins, whose level of prosociality in specific areas was determined by their answers to questions such as “how much obligation would you feel to testify in court about an accident you witnessed?”.
By comparing identical and non-identical twins, the researchers aimed to isolate genetic and environmental factors. They concluded that there were significant differences between men and women in pro-social behaviour, and supported the hypothesis of a common genetic mechanism underlying pro-social behaviours. As the scientists put it in their article in Biological Letters:
“It may be that selection for stable division of work, civil conflicts and welfare behaviours such as obligate food sharing have been important in shaping specific adaptations linked to in-group cooperation.”