Friend or Foe? Early Social Evaluation of Human Interactions

We report evidence that 29-month-old toddlers and 10-month-old preverbal infants discriminate between two agents: a pro-social agent, who performs a positive (comforting) action on a human patient and a negative (harmful) action on an inanimate object, and an anti-social agent, who does the converse. The evidence shows that they prefer the former to the latter even though the agents perform the same bodily movements. Given that humans can cause physical harm to their conspecifics, we discuss this finding in light of the likely adaptive value of the ability to detect harmful human agents.

本研究提供实验证据表明，29月龄学步儿童与10月龄前言语婴儿能够区分两类行动者（agents）：一类为亲社会行动者，其会对人类受动者做出正向（安抚性）行为，而对无生命物体做出负向（伤害性）行为；另一类为反社会行动者，其行为模式恰好相反。实验证据表明，尽管两类行动者的肢体运动完全一致，上述婴幼儿仍更偏爱亲社会行动者而非反社会行动者。鉴于人类能够对同类造成身体伤害，本研究结合辨识具有伤害性人类行动者的能力所可能具备的适应价值，对上述发现展开讨论。