Risk sensitivity, phylogenetic reconstruction, and four chimpanzees.
Risk sensitivity, phylogenetic reconstruction, and four chimpanzees.
复制标题
风险敏感性、系统发育重建和四只黑猩猩。
DOI：
10.1007/s00265-016-2234-8
复制
发表时间：
2017
影响因子：
2.3
通讯作者：
Menzel,CharlesR
中科院分区：
文献类型：
--
作者：
Sayers,Ken;Menzel,CharlesR
对方差或风险的敏感性被认为是经济决策的基础，在灵长类物种典型行为和生殖的讨论中表现突出，并被视为对确定性觅食理论的挑战。大多数风险敏感性研究涉及二分选择和小空间尺度，仅提供有限的基础来预测方差信息如何在不同背景下使用。我们研究了觅食的风险敏感性，在四只黑猩猩（黑猩猩）提出的容器与特定的平均食物奖励/方差。偏好通过室内二分选择测试进行测量。随后的任务，旨在评估这些偏好在不同情况下的表现，涉及不同的食物类型，容器阵列的排序，和/或在大型户外测试区域中恢复它们。此外，一些变化涉及对先前观察到的隐藏容器的记忆。风险偏好因受试者、实验背景、奖励类型和平均奖励数量而异。在等级排序实验中，在奖励条件下，平均食物量是一个更好的预测选择顺序比方差。这些结果带来的问题的论点，物种典型的灵长类动物的风险特征，在持久的意义上，广义的性格特征的有机体已被坚定地确定，并表明，许多流行的实验策略是不足以重建风险相关的特征在灵长类动物/人类进化。来自经典觅食理论的模型，不解决方差，可能是成功的，因为它们包括具有强大预测价值的关键变量。另一方面，确定方差对自然主义决策的重要性，将需要在广泛的实验和观察context.Significance statementStudies风险敏感觅食传统上包括两个选项（不同的方差），涉及相同的食物类型，是接近彼此，是可见的决策者的进一步测试。我们研究了四只黑猩猩的风险敏感性，并包括涉及四个选择选项的实验，不同的食物奖励，增加选项之间的距离，和/或在决策时选择视觉上隐藏的项目。我们发现，黑猩猩表现出对方差的敏感性，可以利用平均数量和方差的关联，即使在某些情况下，当项目是不可见的。然而，当实验环境（例如，奖励类型，可见/隐藏）是不同的。这些结果表明，灵长类动物物种的特定风险偏好的识别还为时过早，风险的研究应该在更广泛的背景下进行。
AbstractSensitivity to variance, or risk, has been considered elementary to economic decision-making, featured prominently in discussions of primate species-typical behaviors and phylogeny and heralded as a challenge to deterministic foraging theory. Most risk sensitivity studies involve dichotomous choices and small spatial scales, providing only limited bases for predicting how variance information might be used across contexts. We examined foraging risk sensitivity in four chimpanzees (Pan troglodytes) which were presented containers associated with particular mean food rewards/variances. Preferences were measured via indoor dichotomous choice tests. Subsequent tasks, designed to assess how well these preferences held up across situations, involved a differing food type, rank-ordering arrays of containers, and/or recovering them in a large outdoor testing area. In addition, some variations involved memory for containers previously observed being hidden. Risk preferences varied by subject, experimental context, reward type, and mean reward quantity. In rank-ordering experiments, under the reward contingencies utilized, mean food quantity was a better predictor of selection order than variance. These results bring into question arguments that species-typical primate risk traits—in the sense of enduring, generalized dispositional features of organisms—have been firmly identified and suggest that many popular experimental strategies are alone inadequate for reconstructing risk-related traits in primate/human evolution. Models from classical foraging theory, which do not address variance, have likely been successful because they include crucial variables with robust predictive value. Determining the importance of variance to naturalistic decision-making, on the other hand, will require further testing in a wide range of experimental and observational contexts.Significance statementStudies of risk-sensitive foraging traditionally include two options (of differing variances) that involve the same food type, are close to one another, and are visible to the decision maker. We examined risk sensitivity in four chimpanzees and included experiments that involved four choice options, differing food rewards, increased distance between options, and/or choosing between items visually hidden at the time of decision-making. We found that chimpanzees exhibited sensitivity to variance and could utilize mean quantity and variance associations—even in some cases when the items were not visible. However, differences within or between individual apes in the strength or direction of risk preferences occurred when experimental context (e.g., reward type, visible/hidden) was varied. These results suggest that identifications of primate species-specific risk preferences are premature and that studies of risk should be conducted in a wider range of contexts.