Brosnan Sarah F, Talbot Catherine, Ahlgren Megan, Lambeth Susan P, Schapiro Steven J
Department of Psychology, Georgia State University, Atlanta, GA, U.S.A.; Neuroscience Institute, Georgia State University, Atlanta, GA, U.S.A.; Michale E. Keeling Center for Comparative Medicine and Research, The University of Texas MD Anderson Cancer Center, Bastrop, TX, U.S.A.
Department of Psychology, Georgia State University, Atlanta, GA, U.S.A.; Michale E. Keeling Center for Comparative Medicine and Research, The University of Texas MD Anderson Cancer Center, Bastrop, TX, U.S.A.
Anim Behav. 2010 Jun 1;79(6):1229-1237. doi: 10.1016/j.anbehav.2010.02.019. Epub 2010 Mar 25.
Several species of nonhuman primates respond negatively to inequitable outcomes, a trait shared with humans. Despite previous research, questions regarding the response to inequity remain. In this study, we replicated the methodology from previous studies to address four questions related to inequity. First, we explored the impact of basic social factors. Second, we addressed whether negative responses to inequity require a task, or exist when rewards are given for 'free'. Third, we addressed whether differences in the experimental procedure or the level of effort required to obtain a reward affected responses. Finally, we explored the interaction between 'individual' expectations (based on one's own previous experience) and 'social' expectations (based on the partner's experience). These questions were investigated in 16 socially housed adult chimpanzees using eight conditions that varied across the dimensions of reward, effort and procedure. Subjects did respond to inequity, but only in the context of a task. Differences in procedure and level of effort required did not cause individuals to change their behaviour. Males were more sensitive to social than to individual expectation, while females were more sensitive to individual expectation. Finally, subjects also increased refusals when they received a better reward than their partner, which has not been documented previously. These results indicate that chimpanzees are more sensitive to reward inequity than procedures, and that there is interaction between social and individual expectations that depends upon social factors.
几种非人类灵长类动物对不公平结果会做出消极反应，这是与人类共有的一种特质。尽管有先前的研究，但关于对不公平的反应仍存在一些问题。在本研究中，我们复制了先前研究的方法，以解决与不公平相关的四个问题。首先，我们探究了基本社会因素的影响。其次，我们探讨了对不公平的消极反应是否需要一项任务，或者在“免费”给予奖励时是否存在。第三，我们探讨了实验程序的差异或获得奖励所需的努力程度是否会影响反应。最后，我们探究了“个体”期望（基于自身先前经验）和“社会”期望（基于伙伴的经验）之间的相互作用。使用奖励、努力和程序维度各不相同的八个条件，在16只群居的成年黑猩猩中对这些问题进行了研究。受试者确实对不公平做出了反应，但仅在任务背景下。程序和所需努力程度的差异并未导致个体改变其行为。雄性对社会期望比对个体期望更敏感，而雌性对个体期望更敏感。最后，当受试者比其伙伴获得更好的奖励时，他们也增加了拒绝行为，这在之前并未有过记录。这些结果表明，黑猩猩对奖励不公平比程序更敏感，并且社会期望和个体期望之间存在取决于社会因素的相互作用。
