The Experts below are selected from a list of 2316 Experts worldwide ranked by ideXlab platform
B. Silvano Zanutto - One of the best experts on this subject based on the ideXlab platform.
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high mutual cooperation rates in rats learning Reciprocal Altruism the role of payoff matrix
PLOS ONE, 2019Co-Authors: Guillermo E. Delmas, Sergio E. Lew, B. Silvano ZanuttoAbstract:Fil: Delmas, Guillermo Ezequiel. Universidad de Buenos Aires. Facultad de Ingenieria; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas; Argentina
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High mutual cooperation rates in rats learning Reciprocal Altruism: The role of payoff matrix.
PloS one, 2019Co-Authors: Guillermo E. Delmas, Sergio E. Lew, B. Silvano ZanuttoAbstract:Cooperation is one of the most studied paradigms for the understanding of social interactions. Reciprocal Altruism -a special type of cooperation that is taught by means of the iterated prisoner dilemma game (iPD)- has been shown to emerge in different species with different success rates. When playing iPD against a Reciprocal opponent, the larger theoretical long-term reward is delivered when both players cooperate mutually. In this work, we trained rats in iPD against an opponent playing a Tit for Tat strategy, using a payoff matrix with positive and negative reinforcements, that is food and timeout respectively. We showed for the first time, that experimental rats were able to learn Reciprocal Altruism with a high average cooperation rate, where the most probable state was mutual cooperation (85%). Although when subjects defected, the most probable behavior was to go back to mutual cooperation. When we modified the matrix by increasing temptation rewards (T) or by increasing cooperation rewards (R), the cooperation rate decreased. In conclusion, we observe that an iPD matrix with large positive reward improves less cooperation than one with small rewards, shown that satisfying the relationship among iPD reinforcement was not enough to achieve high mutual cooperation behavior. Therefore, using positive and negative reinforcements and an appropriate contrast between rewards, rats have cognitive capacity to learn Reciprocal Altruism. This finding allows to infer that the learning of Reciprocal Altruism has early appeared in evolution.
Douglas N. Jackson - One of the best experts on this subject based on the ideXlab platform.
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Kin Altruism, Reciprocal Altruism, and the Big Five Personality Factors
Evolution and Human Behavior, 1998Co-Authors: Michael C Ashton, Edward Helmes, Sampo V Paunonen, Douglas N. JacksonAbstract:Abstract The purpose of this study was to identify personality characteristics associated with kin Altruism and Reciprocal Altruism, and to relate those characteristics to the Big Five personality dimensions. We hypothesized that traits such as empathy and attachment mainly facilitate kin Altruism, and that traits such as forgiveness and non-retaliation mainly facilitate Reciprocal Altruism. Self-report items that we constructed to measure those kinds of personality traits defined two factors as hypothesized. Those factors correlated significantly with external criterion measures intended to represent kin Altruism and Reciprocal Altruism, respectively. Furthermore, correlations with adjective markers of the Big Five indicated that the Empathy/Attachment factor was related positively to Agreeableness and negatively to Emotional Stability, whereas the Forgiveness/Non-Retaliation factor was related positively to both Agreeableness and Emotional Stability.
Guillermo E. Delmas - One of the best experts on this subject based on the ideXlab platform.
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high mutual cooperation rates in rats learning Reciprocal Altruism the role of payoff matrix
PLOS ONE, 2019Co-Authors: Guillermo E. Delmas, Sergio E. Lew, B. Silvano ZanuttoAbstract:Fil: Delmas, Guillermo Ezequiel. Universidad de Buenos Aires. Facultad de Ingenieria; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas; Argentina
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High mutual cooperation rates in rats learning Reciprocal Altruism: The role of payoff matrix.
PloS one, 2019Co-Authors: Guillermo E. Delmas, Sergio E. Lew, B. Silvano ZanuttoAbstract:Cooperation is one of the most studied paradigms for the understanding of social interactions. Reciprocal Altruism -a special type of cooperation that is taught by means of the iterated prisoner dilemma game (iPD)- has been shown to emerge in different species with different success rates. When playing iPD against a Reciprocal opponent, the larger theoretical long-term reward is delivered when both players cooperate mutually. In this work, we trained rats in iPD against an opponent playing a Tit for Tat strategy, using a payoff matrix with positive and negative reinforcements, that is food and timeout respectively. We showed for the first time, that experimental rats were able to learn Reciprocal Altruism with a high average cooperation rate, where the most probable state was mutual cooperation (85%). Although when subjects defected, the most probable behavior was to go back to mutual cooperation. When we modified the matrix by increasing temptation rewards (T) or by increasing cooperation rewards (R), the cooperation rate decreased. In conclusion, we observe that an iPD matrix with large positive reward improves less cooperation than one with small rewards, shown that satisfying the relationship among iPD reinforcement was not enough to achieve high mutual cooperation behavior. Therefore, using positive and negative reinforcements and an appropriate contrast between rewards, rats have cognitive capacity to learn Reciprocal Altruism. This finding allows to infer that the learning of Reciprocal Altruism has early appeared in evolution.
Robert N Brandon - One of the best experts on this subject based on the ideXlab platform.
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why Reciprocal Altruism is not a kind of group selection
Biology and Philosophy, 2011Co-Authors: Grant Ramsey, Robert N BrandonAbstract:Reciprocal Altruism was originally formulated in terms of individual selection and most theorists continue to view it in this way. However, this interpretation of Reciprocal Altruism has been challenged by Sober and Wilson (1998). They argue that Reciprocal Altruism (as well as all other forms of Altruism) evolves by the process of group selection. In this paper, we argue that the original interpretation of Reciprocal Altruism is the correct one. We accomplish this by arguing that if fitness attaches to (at minimum) entire life cycles, then the kind of fitness exchanges needed to form the group-level in such situations is not available. Reciprocal Altruism is thus a result of individual selection and when it evolves, it does so because it is individually advantageous.
Michael Gurven - One of the best experts on this subject based on the ideXlab platform.
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Reciprocal Altruism rather than kin selection maintains nepotistic food transfers on an ache reservation
Evolution and Human Behavior, 2008Co-Authors: Wesley Allenarave, Michael Gurven, Kim HillAbstract:Cooperation among relatives is often regarded as evidence of kin selection. Yet Altruism not requiring shared genes can also evolve among relatives. If characteristics of relatives (such as proximity, familiarity, or trust) make kin preferred social partners, the primary causes of nepotistic biases may reside principally in direct fitness payoffs from cooperation rather than indirect fitness payoffs acquired from aiding collateral kin. We consider the roles of kin selection and Reciprocal Altruism in maintaining nepotistic food transfers on an Ache reservation in northeastern Paraguay. Households do not primarily direct aid to related households that receive larger comparative marginal gains from food intake as we would predict under kin selection theory. Instead, (1) food transfers favor households characterized by lower relative net energy production values irrespective of kinship ties, (2) households display significant positive correlations in amounts exchanged with each other, suggesting contingency in food transfers, and (3) kinship interacts with these positive correlations in amounts households exchange with each other, indicating even stronger contingency in sharing among related households than among unrelated households. While kin are preferred recipients of food aid, food distributions favor kin that have given more to the distributing household in the past rather than kin that would benefit more from the aid. Such discrimination among kin accords better with Reciprocal Altruism theory than with kin selection theory.
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Reciprocal Altruism and food sharing decisions among hiwi and ache hunter gatherers
Behavioral Ecology and Sociobiology, 2004Co-Authors: Michael GurvenAbstract:The common occurrence of food transfers within human hunter–gatherer and forager–horticulturalist groups presents exciting test cases for evolutionary models of Altruism. While kin biases in sharing are consistent with nepotism based on kin selection, there is much debate over the extent to which Reciprocal Altruism and tolerated scrounging provide useful explanations of observed behavior. This paper presents a model of optimal sharing breadth and depth, based on a general non-tit-for-tat form of risk-reduction based Reciprocal Altruism, and tests a series of predictions using data from Hiwi and Ache foragers. I show that large, high variance food items are shared more widely than small, easily acquired food items. Giving is conditional upon receiving in pairwise interactions and this correlation is usually stronger when the exchange of value rather than quantities is considered. Larger families and low producing families receive more and give less, consistent with the notion that marginal value may be a more salient currency than quantity.
