The Evolution of Reciprocal Altruism

1971/03/01 by Robert L. Trivers, Robert Trivers · 1 voice · 11,116 citations
Psychology · Social Sciences · #Altruism (biology) #Cheating #Dishonesty #Economics #Embarrassment #Evolutionary Game Theory and Cooperation #Experimental Behavioral Economics Studies #Game theory #Gratitude #Microeconomics #Psychology #Psychology of Social Influence #Reciprocal #Reciprocal altruism #Reciprocity (cultural anthropology) #Social psychology #Strong reciprocity #Sympathy

paper · doi:10.1086/406755

published in The Quarterly Review of Biology 46(1), 35-57 (University of Chicago Press)

openalex publication_date 1971/03/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06

Abstract

A model is presented to account for the natural selection of what is termed reciprocally altruistic behavior. The model shows how selection can operate against the cheater (non-reciprocator) in the system. Three instances of altruistic behavior are discussed, the evolution of which the model can explain: (1) behavior involved in cleaning symbioses; (2) warning cries in birds; and (3) human reciprocal altruism. Regarding human reciprocal altruism, it is shown that the details of the psychological system that regulates this altruism can be explained by the model. Specifically, friendship, dislike, moralistic aggression, gratitude, sympathy, trust, suspicion, trustworthiness, aspects of guilt, and some forms of dishonesty and hypocrisy can be explained as important adaptations to regulate the altruistic system. Each individual human is seen as possessing altruistic and cheating tendencies, the expression of which is sensitive to developmental variables that were selected to set the tendencies at a balance appropriate to the local social and ecological environment.

Citations

• Trust and suspicion
• The Norm of Reciprocity: A Preliminary Statement

Cited by

• The origins of altruism in offspring care.
• Parent-Offspring Conflict
• An attributional theory of achievement motivation and emotion.
• Fluctuating selection breaks Hamilton’s rule for the evolution of altruism
• Interpersonal Attraction and Relationships
• Is gratitude a moral affect?
• Conflict and reconciliation in two groups of crab-eating monkeys differing in social status by birth
• Possessions and the Extended Self
• Sharing: Table 1
• An Evolutionary Perspective on Bullying and Social Power: The Roles of Cooperation and Manipulation
• Cooperative Evolutionary Pressure and Diminishing Returns Might Explain the Fermi Paradox: On What Super-AIs Are Like
• Evolution of cooperation with temporal information
• Infants' preferences for approachers over repulsers shift between 4 and 8 months of age
• The emotional dog and its rational tail: A social intuitionist approach to moral judgment.
• The future of evolutionary behavioral biology
• Ghosting the Machine: Stop Calling Human-Agent Relations Parasocial
• Payoff equivalence and complete strategy spaces of direct reciprocity
• Multilevel selection theory informs context-dependent mycorrhizal functioning
• The Social Organization of the Common Vampire Bat: I. Pattern and Cause of Association
• SOCIAL DYNAMICS AND COOPERATION: THE CASE OF NONHUMAN PRIMATES AND ITS IMPLICATIONS FOR HUMAN BEHAVIOR
• The structure of multiplex networks predicts play in economic games and real-world cooperation
• Group Formation and the Evolution of Human Social Organization
• Meet me in the middle: potential collaborative benthic hunting in humpback whales (Megaptera novaeangliae)
• The Units of Life
• Indicadores de resultados ("Performances") en la producción del broiler
• Individual and collective gains from cooperation and reciprocity in a dynamic-network Prisoner’s Dilemma driven by extraversion, openness, and agreeableness
• Cooperation in Microbial Populations: Theory and Experimental Model Systems
• Self-interested behaviour as a social norm
• Human newborns spontaneously attend to prosocial interactions
• Altruism and Related Phenomena, Mainly in Social Insects
• Arms races between and within species
• Intuitive ethics: how innately prepared intuitions generate culturally variable virtues
• Edge-based reputation promotes cooperation in simplicial complexes
• Expectation-enforcing strategies for repeated games
• Inducing Cooperative behaviour in Sequential-Social dilemmas through Multi-Agent Reinforcement Learning using Status-Quo Loss
• Selective advantage of redirected helping in a viscous population
• Humpback whales interfering when mammal‐eating killer whales attack other species: Mobbing behavior and interspecific altruism?
• Moral universals: A machine-reading analysis of 256 societies
• Homo cooperans : Understanding the nature of human cooperation
• The Trust Game: A historical and methodological analysis at the frontier of experimental and behavioral economics
• Social semantics: altruism, cooperation, mutualism, strong reciprocity and group selection
• Emotional Rescue: How Affect Helps Partisans Overcome Collective Action Problems
• Analyzing adaptive strategies: Human behavioral ecology at twenty-five
• Evolution of Cooperation in Public Goods Games with Stochastic Opting-Out
• Social game theory: Preferences, perceptions, and choices
• Relationship Valuation Sensitivity for Family and Friends: A Test of Welfare Tradeoff Ratio Variables and General Social Discounting
• Coalitionary intra-group aggression by wild female bonobos
• Diverse and flexible strategies enable successful cooperation in marmoset dyads
• Resolving selfish and spiteful interdependent conflict
• Cultivating multigenerational moral expansion: Interventions cultivate moral concern for future generations in boundless and zero‐sum contexts
• Slow algae, fast fungi: exceptionally high nucleotide substitution rate differences between lichenized fungi Omphalina and their symbiotic green algae Coccomyxa
• Micro-Macro Links and Microfoundations in Sociology
• Consequences of fluctuating group size for the evolution of cooperation
• How does morality work in the brain? A functional and structural perspective of moral behavior
• Reviving, reproducing, and revisiting Axelrod's second tournament
• Facial expression of pain: An evolutionary account
• Money as tool, money as drug: The biological psychology of a strong incentive
• Detect thy family: Mechanisms, ecology and agricultural aspects of kin recognition in plants
• A mutualistic approach to morality: The evolution of fairness by partner choice
• Cooperation, psychological game theory, and limitations of rationality in social interaction
• Future generations hold the lowest moral standing, even below present-day marginalized human and nonhuman outgroups
• The key role of cheaters in the persistence of cooperation
• Understanding the role of hospitality and reciprocity in homestay policy. Support for Ukrainian displaced migrants in the narratives of hosts in Poland and the United Kingdom
• Personality and prosocial behavior: A theoretical framework and meta-analysis.
• Ideological differences in moral concern reflect circle expansion, not inversion
• Young infants prefer prosocial to antisocial others
• The Emergence of Altruism in Large-Language-Model Agents Society
• Protestants and Catholics: Similar Work Ethic, Different Social Ethic
• Apology and forgiveness evolve to resolve failures in cooperative agreements
• Learning Reciprocity in Complex Sequential Social Dilemmas
• The evolution of cooperation under imperfect phenotypic recognition
• Costs and benefits of allomaternal care to mothers and others in wild Phayre's leaf monkeys
• The climate activist’s dilemma: Extreme protests reduce movement support but raise climate concern and intentions
• Aligning Behavioral Assumptions Underlying Policy Instruments: A Principle for Designing Policy Mixes Targeting Behavioral Change
• Differences in adolescents’ motivations for indirect, direct, and hybrid peer defending
• Selfish Memes: An Update of Richard Dawkins’ Bibliometric Analysis of Key Papers in Sociobiology
• Happy to help? A systematic review and meta-analysis of the effects of performing acts of kindness on the well-being of the actor
• Prosocial behavior and altruism: A review of concepts and definitions
• Does gratitude moderate the bystander effect? A registered report
• THE SOCIAL SIGNIFICANCE OF AVIAN WINTER PLUMAGE VARIABILITY
• Evolutionary games on graphs
• Emergence and resilience of cooperation in the spatial Prisoner's Dilemma via a reward mechanism
• Empathy: Its ultimate and proximate bases
• Aggression, science, and law: The origins framework
• Evolutionary dynamics on sequential temporal networks
• The Computational Foundations of Collective Intelligence
• Integrating upstream and downstream reciprocity stabilizes cooperator-defector coexistence in N-player giving games
• A two-player iterated survival game
• Why Do Street-Level Bureaucrats Risk Their Lives in Times of Crisis? The Case of Israeli Police Officers during the October 7 Attack
• A Reputation-Based Model for Decision-Making in Online Social Networks
• Sensitivity-Driven Migration and the Evolution of Cooperation in Multi-Player Games on Structured Populations
• How Much Does Users' Psychology Matter in Engineering Mean-Field-Type Games
• Extortion outperforms generosity in iterated Prisoners' Dilemma
• From gene regulatory networks to social networks: integrative sociogenomics from single cell to superorganism
• Evolutionary dynamics under coordinated reciprocity
• The State of Our Knowledge About Social Knowledge in Platyrrhine Primates: Integrating Decades of Behavioral Observation and Captive Experimentation
• Social dilemmas among unequals
• Higher-order interactions shape collective human behaviour
• Altruism or egoism – how do game features motivate cooperation? An investigation into user we-intention and I-intention
• Coevolution of Cooperation and Partner Rewiring Range in Spatial Social Networks
• Altruistic, more than reputational concerns, drive legacy motives, values, and aspirations across the world
• Evolutionary Stability of Indirect Reciprocity by Image Scoring
• Interactions Among Agent Variables and Evolution of Social Clusters
• Pathways to mutualism breakdown
• Relatedness and synergies of kind and scale in the evolution of helping
• Cooperation begins: Encouraging critical thinking skills through cooperative reciprocity using a mobile learning game
• The rhythm of joint action: Synchrony promotes cooperative ability
• Risk aversion can promote cooperation
• Does strong heterogeneity promote cooperation by group interactions?
• Transition from Gaussian to Levy distributions of stochastic payoff variations in the spatial prisoner’s dilemma game
• Coherence resonance in a spatial prisoner's dilemma game
• Third-party interventions keep social partners from exchanging affiliative interactions with others
• A general model for the evolution of mutualisms
• Cooperation with both synergistic and local interactions can be worse than each alone
• Perceptions, motivators and barriers of using city management applications among citizens: a focus group approach
• Global Convergence for Replicator Dynamics of Repeated Snowdrift Games
• Self-Anchored Attention Model for Sample-Efficient Classification of Prosocial Text Chat
• Redundant relationships in multiplex food sharing networks increase food security in a nutritionally precarious environment
• An Exploratory Examination of the Relationship Between Trust and Street-Level Bureaucrats’ Willingness to Risk Their Lives for Others
• Autocratic Strategies of Multi-State Games
• Strategic Intelligence in Large Language Models: Evidence from evolutionary Game Theory
• Multi-agent Reinforcement Learning in Sequential Social Dilemmas
• The Evolution of Altruistic Rationality Provides a Solution to Social Dilemmas via Rational Reciprocity
• Scaling the human niche
• Modeling Endogenous Social Networks: the Example of Emergence and Stability of Cooperation without Refusal
• Perceptual Rationality: An Evolutionary Game Theory of Perceptually Rational Decision-Making
• Deception in Social Learning: A Multi-Agent Reinforcement Learning Perspective
• Theory of Feeding Strategies
• Digital Ecosystems: Optimisation by a Distributed Intelligence
• Using Large Language Models to Simulate Human Behavioural Experiments: Port of Mars
• Preemptive punishment and the emergence of sanctioning institutions
• BEHAVIORAL ECONOMICS AND EMPIRICAL PUBLIC POLICY
• Revenge is sweet: Investigation of the effects ofApproach‐Motivatedanger on theRewPin the motivated anger delay (MAD) paradigm
• The mechanism of individual time cost heterogeneity promotes cooperation in snowdrift game
• The Evolution of Cooperation
• A framework for the unification of the behavioral sciences
• Serious Games: Human-AI Interaction, Evolution, and Coevolution
• Non-genetic inheritance: Evolution above the organismal level
• Loud Call Production in Male Vervet Monkeys (Chlorocebus pygerythrus) Varies with Season and Signaller Rank
• Investment in By‐Product Benefits (Pseudo‐Reciprocity) Explains the Majority of Help Provided to Non‐Relatives Found in Nature
• A simple model of cognitive processing in repeated games
• Toward a Macroevolutionary Theory of Human Evolution: The Social Protocell
• Why we heal: The evolution of psychological healing and implications for global mental health
• Two-level Fisher-Wright framework with selection and migration: An approach to studying evolution in group structured populations
• The contribution of source–filter theory to mammal vocal communication research
• On the Range of Equilibria Utilities of a Repeated Epidemic Dissemination Game with a Mediator
• Evolution of cooperation and competition in multilayer networks
• Evolution of Cooperative Hunting in Artificial Multi-layered Societies
• Adaptive Decision‐Making “Fast” and “Slow”: A Model of Creative Thinking
• Is evolution always “egolution” : Discussion of evolutionary efficiency of altruistic energy exchange
• “Economic man” in cross-cultural perspective: Behavioral experiments in 15 small-scale societies
• Political Attitudes Vary with Physiological Traits
• Food for Sex in Bats Revealed as Producer Males Reproduce with Scrounging Females
• Monoamine oxidase A gene (MAOA) predicts behavioral aggression following provocation
• The Evolutionary Bases for Sustainable Behavior: Implications for Marketing, Policy, and Social Entrepreneurship
• Runaway Social Selection for Displays of Partner Value and Altruism
• The Market Effect in the Wood Mouse,Apodemus sylvaticus:Selling Information on Reproductive Status
• Value of species and the evolution of conservation ethics
• Slow lies: Response delays promote perceptions of insincerity.
• Evolutionary Psychology: New Perspectives on Cognition and Motivation
• Adaptive specializations, social exchange, and the evolution of human intelligence
• More Effective Choice in the Prisoner's Dilemma
• The emergence of contingent reciprocity in young children
• Altruistic punishment in humans
• The essential moral self
• Game Theory and Biology
• Stephanie Kelton, The Deficit Myth: Modern Monetary Theory and the Birth of the People’s Economy
• Game Theory in the Ecological Context
• Consanguinity as a Major Predictor of Levels of Democracy
• Evolution of indirect reciprocity
• Five Rules for the Evolution of Cooperation
• The nature of human altruism
• Strong Reciprocity and Human Sociality
• TARGET ARTICLE: Selective Investment Theory: Recasting the Functional Significance of Close Relationships
• Altruism as a Handicap: The Limitations of Kin Selection and Reciprocity
• Adam Smith's View of Man
• Ultimate Causation of Aggressive and Forced Copulation in Birds: Female Resistance, the CODE Hypothesis, and Social Monogamy
• The four elementary forms of sociality: Framework for a unified theory of social relations.
• The evolution of strong reciprocity: cooperation in heterogeneous populations
• Dynamical Structure of a Traditional Amazonian Social Network
• Natural language and natural selection
• Towards a balanced social psychology: Causes, consequences, and cures for the problem-seeking approach to social behavior and cognition
• Cooperative hunting roles among taï chimpanzees
• Facial attractiveness in men provides clues to semen quality
• Chimpanzees Recruit the Best Collaborators
• Misrepresentations of Evolutionary Psychology in Sex and Gender Textbooks
• Selectionist Approaches in Evolutionary Linguistics: An Epistemological Analysis
• Cooperation within and among species
• PHILOSOPHICAL EGOISM: ITS NATURE AND LIMITATIONS
• Ontogeny and Social Dominance: A Developmental View of Human Power Patterns
• The sociobiology of sociopathy: An integrated evolutionary model
• Evolution of indirect reciprocity by image scoring
• Selfishness as second-order altruism
• The Evolution of Ethnocentrism
• The bright side of being blue: Depression as an adaptation for analyzing complex problems.
• Sixteen common misconceptions about the evolution of cooperation in humans
• Evolutionary psychology and the generation of culture, part I
• Effect of assessment error and private information on stern-judging in indirect reciprocity
• Social Pressure and Environmental Effects on Networks: A Path to Cooperation
• Evolutionary Game Theory: A Renaissance
• Shame and Psychopathology
• When guilt evokes self-punishment: Evidence for the existence of a Dobby Effect.
• Shame closely tracks the threat of devaluation by others, even across cultures
• High-Cost Altruistic Helping
• Evidence for genetic similarity detection in human marriage
• Male lions in large coalitions gain reproductive advantages
• Psychopathology in great apes: Concepts, treatment options and possible homologies to human psychiatric disorders
• Ventroloquial and Locatable Vocalizations in Birds
• Evolution, Mobility, and Ethnic Group Formation
• A behavioral model of the dual motive approach to behavioral economics and social exchange
• Who's Afraid of the Naturalistic Fallacy?
• Genealogies of Morals: Nietzsche's Method Compared
• Capuchin cognitive ecology: cooperation based on projected returns
• Corporate Social Responsibility Does Not Avert the Tragedy of the Commons -- Case Study: Coca-Cola India
• On Hotheads and Dirty Harries
• Fighting Poverty in the US and Europe
• Ecology, Sexual Selection, and the Evolution of Mating Systems
• NATURAL SELECTION AND THE PROBLEM OF EVIL: AN EVOLUTIONARY MODEL WITH APPLICATION TO AN ANCIENT DEBATE
• Mate selection—A selection for a handicap
• Toward a Functional Interpretation of Synchronous Flashing by Fireflies
• Talk, Judge, Cooperate: Gossip-Driven Indirect Reciprocity in Self-Interested LLM Agents
• Mother-pup separation and adoption in northern elephant seals
• The New Synthesis in Moral Psychology
• Essay Review: Sociobiology: Twenty-Five Years Later
• Punishment allows the evolution of cooperation (or anything else) in sizable groups
• Collective Action and the Evolution of Social Norms
• Putting the Altruism Back into Altruism: The Evolution of Empathy
• The hearing of an avian predator and its avian prey
• Prisoner’s dilemma on a stochastic nongrowth network evolution model
• Good Guys Can Finish First: How Brand Reputation Affects Extension Evaluations
• On Human Altruism: The Discrepancy between Normative and Factual Conclusions
• Persistent cooperators in nature
• Grooming and the Expectation of Reciprocation in Mandrills (Mandrillus sphinx)
• Mutualism, reciprocity, or kin selection? Cooperative rescue of a conspecific from a boa in a nocturnal solitary forager the gray mouse lemur
• When to be a dear enemy: flexible acoustic relationships of neighbouring skylarks, Alauda arvensis
• Life Histories, Blood Revenge, and Warfare in a Tribal Population
• Reward and cooperation in the spatial public goods game
• Cooperative bird differentiates between the calls of different individuals, even when vocalizations were from completely unfamiliar individuals
• From the Selfish Gene to the “We”: Cooperation Often Needs Suppressors
• When Morality Opposes Justice: Conservatives Have Moral Intuitions that Liberals may not Recognize
• The Sympathetic Plot, Its Psychological Origins, and Implications for the Evolution of Fiction
• Mapping morality with a compass: Testing the theory of ‘morality-as-cooperation’ with a new questionnaire
• Mapping the moral domain.
• Moral Foundations Theory
• Harm to others outweighs harm to self in moral decision making
• Evolution and Moral Diversity
• Moral psychology for the twenty-first century
• Learning a commonsense moral theory
• A meta-analytic investigation of the relation between interpersonal attraction and enacted behavior.
• The Neural Mechanisms of Meditative Practices: Novel Approaches for Healthy Aging
• PARTIAL INCOMPATIBILITY BETWEEN ANTS AND SYMBIOTIC FUNGI IN TWO SYMPATRIC SPECIES OF ACROMYRMEX LEAF-CUTTING ANTS
• Hadza meat sharing
• Turtle hunting and tombstone opening
• Bargaining theory and cooperative fishing participation on ifaluk atoll
• Showing off
• Showing off, handicap signaling, and the evolution of men's work
• Evolution of signalling through pursuit deterrence in a two-prey model using game theory
• Food Transfers Among Hiwi Foragers of Venezuela: Tests of Reciprocity
• Islam and Evolution
• The Evolution, Function, and Meaning of Marmot Alarm Communication
• Emergence of Reputation-Based Cooperation in LLM Agents
• Autocratic strategies for iterated games with arbitrary action spaces
• Why Liberals and Atheists Are More Intelligent
• The social organization of the common vampire bat
• From extortion to generosity, evolution in the Iterated Prisoner’s Dilemma
• Signalling boosts the evolution of cooperation in repeated group interactions
• Does food sharing in vampire bats demonstrate reciprocity?
• Can Deep Altruism Sustain Space Settlement?
• Promoting cooperation by preventing exploitation: The role of network structure
• Language structure in then-object naming game
• Co-action provides rational basis for the evolutionary success of Pavlovian strategies
• The recommendation system to SNS community for tourists by using altruistic behaviors
• The evolution of misbelief
• Dirt, Disgust, and Disease: Is Hygiene in Our Genes?
• The emergence of biosphere entrepreneurship: are social and business entrepreneurship obsolete?
• Group-Level Imitation May Stabilize Cooperation
• Evolutionary psychology [wikipedia]
• Helping behavior [wikipedia]
• Liberalism [wikipedia]
• Natural selection [wikipedia]
• Richard Dawkins [wikipedia]
• The Evolution of Cooperation [wikipedia]
• Tragedy of the commons [wikipedia]
• What's in it for me? Self-regard precludes altruism and spite in chimpanzees. [europepmc]
• Evolutionary games on cycles. [europepmc]
• Evolutionary games and population dynamics: maintenance of cooperation in public goods games. [europepmc]
• Upstream reciprocity and the evolution of gratitude. [europepmc]
• Partner choice creates competitive altruism in humans. [europepmc]
• High-testosterone men reject low ultimatum game offers. [europepmc]
• Evolution of direct and indirect reciprocity. [europepmc]
• Grooming reciprocation among female primates: a meta-analysis. [europepmc]
• The economics of altruistic punishment and the maintenance of cooperation. [europepmc]
• Altruism [wikipedia]
• Reciprocity, culture and human cooperation: previous insights and a new cross-cultural experiment. [europepmc]
• Dopamine regulation of social choice in a monogamous rodent species. [europepmc]
• Social evolution in micro-organisms and a Trojan horse approach to medical intervention strategies. [europepmc]
• Evolutionary dynamics in structured populations. [europepmc]
• Host sanctions and pollinator cheating in the fig tree-fig wasp mutualism. [europepmc]
• Reasons for participating in randomised controlled trials: conditional altruism and considerations for self. [europepmc]
• How life history and demography promote or inhibit the evolution of helping behaviours. [europepmc]
• Prosocial primates: selfish and unselfish motivations. [europepmc]
• On the psychology of cooperation in humans and other primates: combining the natural history and experimental evidence of prosociality. [europepmc]
• Match and mismatch: conservation physiology, nutritional ecology and the timescales of biological adaptation. [europepmc]
• A construct divided: prosocial behavior as helping, sharing, and comforting subtypes. [europepmc]
• Correlated pay-offs are key to cooperation. [europepmc]
• Reputation, a universal currency for human social interactions. [europepmc]
• Biological trade and markets. [europepmc]
• Cooperation and the evolution of hunter-gatherer storytelling. [europepmc]
• Long-term reciprocation of grooming in wild West African chimpanzees. [europepmc]

Discussions

• La morale, dans TON intérêt ? [lemmy, 1 points, 0 comments]

Related

• Putting the Altruism Back into Altruism: The Evolution of Empathy
• Selfishness as second-order altruism
• Altruism may arise from individual selection
• Altruism: A Review of Recent Theory and Research
• Genes underlying altruism