Reciprocal altruism

Reciprocal altruism
Tomatose · CC BY-SA 3.0 · source
Name	Reciprocal altruism
Field	Evolutionary biology, Behavioral ecology, Psychology

Contents

Reciprocal altruism

Reciprocal altruism is a behavioral phenomenon in which an individual incurs a cost to provide a benefit to another, with the expectation that the favor will be returned in the future. It is central to explanations in evolutionary biology, behavioral ecology, and social psychology for cooperation among nonkin, and has been discussed in relation to work by Charles Darwin, William D. Hamilton, Robert Trivers, John Maynard Smith, and institutions such as the Royal Society, Max Planck Society, Smithsonian Institution, and University of Cambridge.

Definition and theoretical framework

Reciprocal altruism was formalized within frameworks developed by Robert Trivers, W. D. Hamilton, John Maynard Smith, George C. Williams, and popularized in texts from Charles Darwin and the Royal Society proceedings. Models draw on concepts from game theory, notably the Prisoner's Dilemma, analyses by Robert Axelrod, and mathematical treatments linked to work from William Hamilton and Hamilton's rule. Foundational discussions occurred at venues such as Cold Spring Harbor Laboratory, in journals edited by Edward O. Wilson and institutions like Harvard University, Oxford University, and University of Chicago.

Mechanistic explanations use kin selection contrasts by W. D. Hamilton and evolutionary stable strategy (ESS) analysis by John Maynard Smith and George R. Price. Iterated interactions are modeled via the Prisoner's Dilemma tournaments curated by Robert Axelrod, strategies such as tit for tat and variations studied in contexts associated with Santa Fe Institute, Los Alamos National Laboratory, and departments at Massachusetts Institute of Technology, Princeton University, and Stanford University. Simulation studies build on methods from Alan Turing-inspired computation and work published in outlets tied to Nature (journal), Science (journal), and Proceedings of the National Academy of Sciences.

Empirical cases have been reported across taxa. In primates, observations by researchers affiliated with Jane Goodall Institute, Primate Research Institute, Max Planck Institute for Evolutionary Anthropology, and field sites in Gombe Stream National Park, Taï National Park, and Khao Yai National Park document food sharing and grooming reciprocity among species such as Pan troglodytes and Macaca fascicularis. Avian examples reported from studies at Cornell Lab of Ornithology and British Trust for Ornithology include reciprocal mobbing in Corvus corone and cooperative provisioning in Amazona amazonica contexts described by researchers at University of Oxford and University of Cambridge. Marine examples linked to work at Scripps Institution of Oceanography and Woods Hole Oceanographic Institution include cleaning mutualisms involving Labroides dimidiatus and client fishes documented by teams from University of Queensland and James Cook University. Microbial and plant systems with exchange of resources or signals have been explored by groups at Max Planck Society, John Innes Centre, and University of California, Berkeley.

The viability of reciprocal mechanisms depends on cost-benefit balances analogous to parameters in Hamilton's rule and payoff matrices from game theory tournaments analyzed by Robert Axelrod and colleagues at University of Michigan and University of Pennsylvania. Stability criteria reference cheater detection and punishment mechanisms studied by researchers at London School of Economics, University College London, and Yale University; demographic structure and repeated interaction assumptions connect to models developed at University of Oxford and Princeton University. Empirical work examining longevity of partnerships and memory constraints cites experiments and longitudinal studies from Harvard University, University of California, Los Angeles, and University of Chicago.

Human reciprocity has been investigated by interdisciplinary teams at Harvard University, University of Oxford, University of Cambridge, Stanford University, Yale University, London School of Economics, and the Max Planck Institute for Human Cognitive and Brain Sciences. Anthropological fieldwork in places such as Trobriand Islands, Papua New Guinea, Amazon Basin, Ethiopia, and among societies studied by Marshall Sahlins and Claude Lévi-Strauss documents gift exchange and obligation rules; economic experiments including ultimatum and public goods games run at University of Pennsylvania and University of Chicago show cultural variation influenced by norms promulgated via institutions like United Nations Educational, Scientific and Cultural Organization and World Bank. Neurobiological correlates have been mapped in studies at National Institutes of Health, MIT, and University College London linking reciprocity to activation in regions cited in work by Antonio Damasio and Michael Gazzaniga.

Critiques and alternative explanations have been advanced by scholars at University of California, Berkeley, Princeton University, University of Oxford, and University of Chicago. Alternatives include pseudo-reciprocity explored in literature from American Naturalist and Ecology Letters, partner choice models developed at Santa Fe Institute, and group selection perspectives revitalized by work associated with E.O. Wilson and debates at Harvard University and Royal Society. Methodological controversies concern inference from observational data raised by researchers at Max Planck Institute for Evolutionary Anthropology and statistical critiques emerging from groups at Columbia University and Stanford University. Ongoing disputes appear in forums such as conferences at Society for the Study of Evolution, symposia at International Society for Behavioral Ecology, and editorial exchanges in Nature and Science.