Variant at serotonin transporter gene predicts increased imitation in toddlers: relevance to the human capacity for cumulative culture

Cumulative culture ostensibly arises from a set of sociocognitive processes which includes high-fidelity production imitation, prosociality and group identification. The latter processes are facilitated by unconscious imitation or social mimicry. The proximate mechanisms of individual variation in imitation may thus shed light on the evolutionary history of the human capacity for cumulative culture. In humans, a genetic component to variation in the propensity for imitation is likely. A functional length polymorphism in the serotonin transporter gene, the short allele at 5HTTLPR, is associated with heightened responsiveness to the social environment as well as anatomical and activational differences in the brain's imitation circuity. Here, we evaluate whether this polymorphism contributes to variation in production imitation and social mimicry. Toddlers with the short allele at 5HTTLPR exhibit increased social mimicry and increased fidelity of demonstrated novel object manipulations. Th...累积文化（Cumulative culture）表面上源自一系列社会认知过程，涵盖高保真生产模仿、亲社会性与群体认同。后述过程可通过无意识模仿或社会模仿（social mimicry）得到促进。因此，个体模仿行为差异的近缘机制，或可为人类累积文化能力的进化历程提供关键洞察。就人类而言，模仿倾向的个体差异大概率存在遗传基础。血清素转运蛋白基因（serotonin transporter gene）中存在一处功能性长度多态性，即5HTTLPR位点的短等位基因，该多态性与个体对社会环境的敏感性增强，以及大脑模仿回路的解剖结构与激活模式差异相关。本研究旨在探究该多态性是否会导致生产模仿与社会模仿行为出现个体差异。携带5HTTLPR短等位基因的幼儿，其社会模仿行为更为显著，且对演示的新颖物体操作方式的模仿保真度更高。...