Are apes inequity averse? New data on the token‐exchange paradigm

@article{Bruer2009AreAI,
  title={Are apes inequity averse? New data on the token‐exchange paradigm},
  author={Juliane Br{\"a}uer and Josep Call and Michael Tomasello},
  journal={American Journal of Primatology},
  year={2009},
  volume={71}
}
Recent studies have produced mixed evidence about inequity aversion in nonhuman primates. Brosnan et al. [Proceedings of the Royal Society of London. Series B. Biological Sciences 272:253–258, 2005] found inequity aversion in chimpanzees and argued that effort is crucial, if subjects are to evaluate how they are rewarded in comparison to a competitor for an identical performance. In this study we investigated inequity aversion with chimpanzees, bonobos and orangutans, using the method of… 
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No evidence of an aversion to inequitable outcomes is found in the kea when there was a difference between reward quality or working effort required between actor and partner.
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Goffins showed some sensitivity to increased unequal work-effort, but did not react to unequal reward distribution, and was tested for the first time a Cacatua, the Goffin's cockatoo, using a standardized token exchange paradigm in which first the partner and then the subject could exchange a token for a food reward.
Inequity aversion in dogs: a review
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A comprehensive discussion of two understudied aspects of inequity aversion, the underlying mechanisms and the ultimate function in dogs are provided, drawing on the latest findings on these topics in dogs while also placing these developments in the context of what is known, or thought to be the case, in other non-human animal species.
Young children, but not chimpanzees, are averse to disadvantageous and advantageous inequities.
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Parrots may not exhibit inequity aversion due to interdependence on their life-long partner and the high costs associated with finding a new partner, and this work tests four parrot species in the token exchange paradigm, finding none of the species responded to inequity in terms of effort.
Social disappointment explains chimpanzees' behaviour in the inequity aversion task
TLDR
It is found that chimpanzees were more likely to reject food when it was distributed by an experimenter rather than by a machine and that they were not morelikely to do so when a partner was present.
The Influence of the Relationship and Motivation on Inequity Aversion in Dogs
TLDR
The findings of two studies of dogs’ responses to inequity and the social factors that mediate such responses suggest that inequity aversion in dogs is conditional on their and their partner’s rewards.
Investigating reactions of squirrel monkeys (Saimiri sciureus) towards unequal food distributions in a tray-pulling paradigm
TLDR
Results showed that female donors pulled the tray less often in the quantitative inequity condition with an out-group female recipient than when alone, and point towards possible disadvantageous inequity aversion in female squirrel monkeys.
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References

SHOWING 1-10 OF 35 REFERENCES
Are apes really inequity averse?
TLDR
The most plausible explanation for these results is the food expectation hypothesis—seeing another individual receive high-quality food creates the expectation of receiving the same food oneself—and not inequity aversion.
Tolerance for inequity may increase with social closeness in chimpanzees
TLDR
It is demonstrated that, like capuchin monkeys, chimpanzees show a response to inequity of rewards that is based upon the partner receiving the reward rather than the presence of the reward alone.
Monkeys reject unequal pay
TLDR
It is demonstrated that a nonhuman primate, the brown capuchin monkey (Cebus apella), responds negatively to unequal reward distribution in exchanges with a human experimenter, supporting an early evolutionary origin of inequity aversion.
Effects of food preferences on token exchange and behavioural responses to inequality in tufted capuchin monkeys, Cebus apella
Inequity responses of monkeys modified by effort
TLDR
The sensitivity to reward division in brown, or tufted, capuchin monkeys (Cebus apella) is documents and effects are as expected if the inequity response evolved in the context of cooperative survival strategies.
Partner effects on food consumption in brown capuchin monkeys
TLDR
The findings differed from those of other authors in that the monkeys failed to show negative reactions to inequity, but rather responded with scramble competition in the presence of a conspecific without access to food.
Are capuchin monkeys (Cebus apella) inequity averse?
TLDR
It is argued that capuchins' refusals were due to the frustration of seeing and not obtaining the PF, and that seeing the partner eating increases the LPF acceptance.
Chimpanzees are indifferent to the welfare of unrelated group members
TLDR
Experimental tests of the existence of other-regarding preferences in non-human primates are presented and it is shown that chimpanzees (Pan troglodytes) do not take advantage of opportunities to deliver benefits to familiar individuals at no material cost to themselves, suggesting that chimpanzee behaviour is not motivated by other- Regarding preferences.
What's in it for me? Self-regard precludes altruism and spite in chimpanzees
TLDR
The main result across all studies was that chimpanzees made their choices based solely on personal gain, with no regard for the outcomes of a conspecific.
The Social Behavior of Chimpanzees and Bonobos: Empirical Evidence and Shifting Assumptions1
As our closest living relatives, chimpanzees and bonobos have been widely used as models of the behavior of early hominids. In recent years, as information on the social behavior and ecology of…
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