Where does reciprocity collide?

A generalised moral rule that obliges people to return the benefits they receive and to refrain from harming those who have helped them. Gouldner's 1960 The Norm of Reciprocity: A Preliminary Statement argued that this norm is nearly universal across societies and helps hold exchange relationships together by making an unrepaid favour feel like a standing debt. The referent is a shared social expectation about how people ought to treat one another, measured by attitudes and behaviour, not a strategy that spreads by natural selection, a pattern of choices in an economic game, or a theorem about numbers.[1]

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A felt obligation to repay a benefit, held as a social norm

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Not applicable

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Studied through surveys, observation of exchange, and field or laboratory tests of whether people return favours

A pattern in which one organism helps another at a cost to itself because the favour is likely to be returned later, so that both do better over repeated encounters. Trivers's 1971 The Evolution of Reciprocal Altruism showed how such helping can be favoured by natural selection when animals interact many times and can detect and stop cooperating with those who fail to return help. The referent is a behaviour that spreads because it raises reproductive success, explained by evolutionary theory, not a moral duty people feel, a choice in a laboratory game, or a result in number theory.[2]

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A costly helping act that raises fitness through later return

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Not applicable

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Inferred from repeated helping in the wild and from models and experiments where cooperation is conditional on past help

A behavioural tendency to reward those who have been kind and to punish those who have been unkind, even when doing so is costly and brings no future gain. Fehr and Gachter's 2000 Fairness and Retaliation: The Economics of Reciprocity gathered game experiments showing that many people repay generosity with generosity and betrayal with punishment, which changes how contracts and markets work. The referent is a measured disposition in strategic decisions, observed through payoffs in controlled games, not a broad social norm, an evolved animal behaviour, or a mathematical theorem.[3]

Unit

A costly response that rewards kindness or punishes unkindness

Recovery means

Not applicable

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Quantified in trust, gift-exchange, and public-good games by how choices track the other party's prior behaviour

A theorem in the study of whole numbers that links, for two odd prime numbers, the question of whether the first is a perfect square modulo the second to whether the second is a perfect square modulo the first. Gauss proved this law of quadratic reciprocity in his 1801 Disquisitiones Arithmeticae, calling it a jewel of arithmetic and giving the first complete demonstration. The referent is a proven mathematical relationship between number problems, true by deduction, not a social norm, an evolved behaviour, or a pattern of choices people make in games.[4]

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A theorem relating the solvability of two quadratic congruences

Recovery means

Not applicable

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Established by mathematical proof and applied in tests for whether a number is a square modulo a prime

In public health ethics, reciprocity refers to the duty of society to support people who bear burdens for the public's health, such as those placed in quarantine. This meaning comes from Upshur (2002) in Canadian Journal of Public Health.[5]

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