School of Biology, St Andrews University, St Andrews, UK.
Biol Lett. 2010 Aug 23;6(4):466-8. doi: 10.1098/rsbl.2009.1014. Epub 2010 Feb 3.
Theoretical analyses have reported that in most circumstances where natural selection favours reliance on social learning, conformity (positive frequency-dependent social learning) is also favoured. These findings suggest that much animal social learning should involve a copy-the-majority strategy, yet there is currently surprisingly little evidence for conformist learning among animals. Here, we investigate this possibility in the nine-spined stickleback (Pungitius pungitius) by manipulating the number of demonstrator fish at two feeders, one rich and one poor, during a demonstration phase and evaluating how this affects the likelihood that the focal fish copy the demonstrators' apparent choices. As predicted, we observed a significantly increased level of copying with increasing numbers of demonstrators at the richer of the two feeders, with copying increasing disproportionately, rather than linearly, with the proportion of demonstrators at the rich foraging patch. Control conditions with non-feeding demonstrators showed that this was not simply the result of a preference for shoaling with larger groups, implying that nine-spined sticklebacks copy in a conformist manner.
理论分析报告称，在大多数自然选择有利于依赖社会学习的情况下，从众（积极的频率依赖型社会学习）也会受到青睐。这些发现表明，许多动物的社会学习应该涉及复制多数策略，但目前动物中从众学习的证据却少得惊人。在这里，我们通过在演示阶段操纵两个喂食器（一个丰富，一个贫穷）中展示鱼的数量来研究九刺鱼（Pungitius pungitius）中的这种可能性，评估这如何影响焦点鱼复制展示者明显选择的可能性。正如预测的那样，我们观察到，在两个喂食器中较丰富的一个喂食器中，随着展示者数量的增加，复制的水平显著增加，而不是与富觅食斑块上展示者的比例呈线性增加。没有喂食的展示者的对照条件表明，这不仅仅是因为更喜欢与较大的群体聚集，这意味着九刺鱼以从众的方式进行复制。
