Aplin Lucy M, Sheldon Ben C, McElreath Richard
Edward Grey Institute, Department of Zoology, University of Oxford, Oxford OX1 3PS, United Kingdom;
Edward Grey Institute, Department of Zoology, University of Oxford, Oxford OX1 3PS, United Kingdom.
Proc Natl Acad Sci U S A. 2017 Jul 25;114(30):7830-7837. doi: 10.1073/pnas.1621067114. Epub 2017 Jul 24.
Social learning is important to the life history of many animals, helping individuals to acquire new adaptive behavior. However despite long-running debate, it remains an open question whether a reliance on social learning can also lead to mismatched or maladaptive behavior. In a previous study, we experimentally induced traditions for opening a bidirectional door puzzle box in replicate subpopulations of the great tit Individuals were conformist social learners, resulting in stable cultural behaviors. Here, we vary the rewards gained by these techniques to ask to what extent established behaviors are flexible to changing conditions. When subpopulations with established foraging traditions for one technique were subjected to a reduced foraging payoff, 49% of birds switched their behavior to a higher-payoff foraging technique after only 14 days, with younger individuals showing a faster rate of change. We elucidated the decision-making process for each individual, using a mechanistic learning model to demonstrate that, perhaps surprisingly, this population-level change was achieved without significant asocial exploration and without any evidence for payoff-biased copying. Rather, by combining conformist social learning with payoff-sensitive individual reinforcement (updating of experience), individuals and populations could both acquire adaptive behavior and track environmental change.
社会学习对许多动物的生活史很重要,它帮助个体习得新的适应性行为。然而,尽管长期存在争议,但依赖社会学习是否也会导致行为不匹配或适应不良,这仍然是一个悬而未决的问题。在之前的一项研究中,我们在大山雀的重复亚群体中通过实验诱导出打开双向门拼图盒的传统行为。个体是遵循群体规范的社会学习者,从而产生了稳定的文化行为。在此,我们改变通过这些技巧获得的奖励,以探究既定行为在多大程度上能灵活适应不断变化的条件。当采用一种技巧建立了觅食传统的亚群体面临觅食回报降低的情况时,49%的鸟类在仅仅14天后就将其行为转变为回报更高的觅食技巧,较年轻的个体表现出更快的变化速度。我们阐明了每个个体的决策过程,使用一个机械学习模型来证明,也许令人惊讶的是,这种群体层面的变化是在没有显著的非社会探索且没有任何回报偏向性模仿证据的情况下实现的。相反,通过将遵循群体规范的社会学习与对回报敏感的个体强化(经验更新)相结合,个体和群体都能够习得适应性行为并追踪环境变化。