Much of this information has been touched on in other nodes, regardless, I will present reciprocal altruism as it applies to the biological sciences (also I felt the need to fill up this poor empty node).


  • The fundamental idea of reciprocal altruism is that animals may behave altruistically towards non-relatives if they have a high likelihood of receiving future aid in reward for their actions. See also: The Prisoner's Dilemma.

  • There are three necessary conditions for the evolution of reciprocal altruism to take place.

    1. Repeated pairwise interactions are needed to permit role exchanges between donor and beneficiary.
    2. The benefit of receiving aid must exceed the cost of donating.
    3. Donors must be able to recognize partners, remember their previous actions and refuse to cooperate with previous individuals that did not reciprocate.
  • What are the skills are necessary in a species to allow for the capacity of reciprocal altruism?
    1. The individuals of the species must be able to recognize, remember, and retaliate.
    2. Again, they must be able to benefit from the action, and this benefit must outweigh the potential cost of the altruistic action.
    3. The species in question must be reasonably social, i.e., there must be repeated social interactions between members of the species.

  • The biggest difference between traditional altruism and reciprocal altruism lies in the context of the supposedly altruistic action. According to traditional altruism, costly actions are more likely to performed for the benefit of a relative who shares genes with the performer. This is known as kin selection. Additionally, the performer's reproductive success may be increased if the altruistic action is successful. Even if the action is not successful, the relative's genes may be passed on. Reciprocal altruism is not dependent upon the genetics of the individuals involved.

  • Information is taken from Joan Strassmann's lecture on 11/01/00, entitled Reciprocal Altruism: Cooperation Between Animals. As of right now (12/02/04) you may find a copy of the lecture notes at this location: http://dacnet.rice.edu/courses/bios321/lectures/Class11Recipalthtml/sld001.htm