Data from: Kin recognition: evidence that humans can perceive both positive and negative relatedness

The evolution of spite entails actors imposing costs on ‘negative’ relatives: those who are less likely than chance to share the actor’s alleles and therefore more likely to bear rival alleles. Yet, despite a considerable body of research confirming that organisms can recognise positive relatives, little research has shown that organisms can recognise negative relatives. Here, we extend previous work on human phenotype matching by introducing a cue to negative relatedness: negative self-resembling faces, which differ from an average face in the opposite direction to the way an individual’s own face differs from the average. Participants made trustworthiness and attractiveness judgements of pairs of opposite-sex positive and negative self-resembling faces. Analyses revealed opposing effects of positive and negative self-resembling faces on trustworthiness and attractiveness judgements. This is the first clear evidence that humans are sensitive to negative relatedness cues, and suggests potential for the adaptive allocation of spiteful behaviour.

恶意行为（spite）的演化机制，指行为主体对‘负亲缘个体’施加生存或繁殖代价：这类个体与行为主体共享等位基因（alleles）的概率低于随机水平，因此更易携带对立等位基因。尽管已有大量研究证实生物可识别正亲缘个体，但目前鲜有研究表明生物能够识别负亲缘个体。本研究拓展了此前关于人类表型匹配（human phenotype matching）的研究，引入了负亲缘关系的识别线索——自我负相似面孔：即与平均面孔的差异方向，恰好与个体自身面孔和平均面孔的差异方向相反。实验参与者需对成对的异性自我正相似面孔与自我负相似面孔，进行可信赖度与吸引力评分。分析结果显示，自我正相似与自我负相似面孔对可信赖度与吸引力评价产生了相反的影响。本研究首次明确证实人类对负亲缘关系线索具有敏感性，同时暗示了损他性行为的适应性分配潜力。