Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland; Inkawu Vervet Project, Swart Mfolozi, PO Box 84, KwaZulu Natal, 3115, South Africa.
Inkawu Vervet Project, Swart Mfolozi, PO Box 84, KwaZulu Natal, 3115, South Africa; Centre for Social Learning & Cognitive Evolution, School of Psychology and Neuroscience, University of St Andrews, St Andrews Fife, KY169JU, UK.
Curr Biol. 2018 Sep 10;28(17):2800-2805.e4. doi: 10.1016/j.cub.2018.06.015. Epub 2018 Aug 30.
Social learning in animals is now well documented, but few studies have determined the contexts shaping when social learning is deployed. Theoretical studies predict copying of conspecifics gaining higher payoffs [1-4], a bias demonstrated in primates only in captivity [5]. In the wild, research has shown selective attention toward the philopatric sex, a group's stable core [6]. Here, we report the first rigorous experimental test of the existence of a payoff bias in wild primates and its interaction with the sex of the model. We created a payoff bias in which an immigrant alpha male in each of three groups of wild vervet monkeys received five times more food upon opening a foraging box than did the philopatric alpha female, whereas in two control groups, male and female models received the same amount of food. We tested whether this payoff asymmetry would override the previously documented selective learning from resident females. Group members were tested after having watched both models. When both models received the same amount of food, audience members copied the female model significantly more than the male model, confirming previous findings. However, when a marked payoff bias was introduced, male, but not female, vervet monkeys significantly more often copied the male model receiving a higher payoff. These results demonstrate behavioral flexibility in the dispersing sex in these primates and suggest that the philopatric sex can afford to be more conservative in their social learning. Our findings show that multiple social-learning biases can coexist and interact within the same species.
动物的社会学习现在已经得到了充分的证明，但很少有研究确定了影响社会学习的情境。理论研究预测，动物会模仿获得更高回报的同类[1-4]，而这种模仿偏见仅在圈养的灵长类动物中得到了证明[5]。在野外，研究表明，动物会选择性地关注同种的、有亲缘关系的、稳定的核心群体[6]。在这里，我们首次在野外灵长类动物中进行了严格的实验测试，以验证存在收益偏好的假设及其与模型性别之间的相互作用。我们在三个野生草原猴群中引入了一种收益偏好，即每个猴群中的一个移民雄性阿尔法猴在打开觅食箱时获得的食物比留居雌性阿尔法猴多五倍，而在两个对照组中，雄性和雌性模型获得的食物量相同。我们测试了这种收益不对称性是否会压倒之前从留居雌性中记录到的选择性学习。在观看了两个模型后，对猴群成员进行了测试。当两个模型获得相同数量的食物时，观众明显更多地模仿雌性模型，而不是雄性模型，这证实了之前的发现。然而，当引入明显的收益偏好时，雄性而不是雌性草原猴更多地模仿获得更高收益的雄性模型。这些结果表明，在这些灵长类动物中，分散的雄性具有行为灵活性，并表明留居的雌性可以在其社会学习中更保守。我们的研究结果表明，在同一物种中，多种社会学习偏见可以共存并相互作用。
