Centre for Evolutionary Biology, School of Biological Sciences, University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia.
Centre for Ecology and Conservation, University of Exeter, Penryn Campus, Treliever Road, Penryn TR10 9FE, UK.
Nature. 2018 Feb 15;554(7692):364-367. doi: 10.1038/nature25503. Epub 2018 Feb 7.
The social intelligence hypothesis states that the demands of social life drive cognitive evolution. This idea receives support from comparative studies that link variation in group size or mating systems with cognitive and neuroanatomical differences across species, but findings are contradictory and contentious. To understand the cognitive consequences of sociality, it is also important to investigate social variation within species. Here we show that in wild, cooperatively breeding Australian magpies, individuals that live in large groups show increased cognitive performance, which is linked to increased reproductive success. Individual performance was highly correlated across four cognitive tasks, indicating a 'general intelligence factor' that underlies cognitive performance. Repeated cognitive testing of juveniles at different ages showed that the correlation between group size and cognition emerged in early life, suggesting that living in larger groups promotes cognitive development. Furthermore, we found a positive association between the task performance of females and three indicators of reproductive success, thus identifying a selective benefit of greater cognitive performance. Together, these results provide intraspecific evidence that sociality can shape cognitive development and evolution.
社会智力假说指出，社会生活的需求推动了认知进化。这一观点得到了比较研究的支持，这些研究将群体大小或交配系统的变化与物种间的认知和神经解剖差异联系起来，但研究结果存在矛盾和争议。为了了解社会性的认知后果，研究物种内的社会性变化也很重要。在这里，我们表明，在野生的、合作繁殖的澳大利亚喜鹊中，生活在大群体中的个体表现出更高的认知能力，这与更高的繁殖成功率有关。个体表现与四项认知任务高度相关，表明存在一个“一般智力因素”，这是认知表现的基础。对不同年龄的青少年进行重复的认知测试表明，群体大小与认知之间的相关性出现在生命早期，这表明生活在更大的群体中促进了认知发展。此外，我们还发现了女性任务表现与三种繁殖成功率指标之间的正相关，从而确定了更高认知表现的选择优势。总之，这些结果提供了种内证据，表明社会性可以塑造认知发展和进化。
