Social groups often consist of diverse phenotypes, including personality types, and this diversity is known to affect the functioning of the group as a whole. Social selection theory proposes that group composition (i.e. social environment) also influences the performance of individual group members. However, the effect of group behavioural composition on group members remains largely unexplored, and it is still contentious whether individuals benefit more in a social environment with homogeneous or diverse behavioural composition. We experimentally formed groups of house sparrows Passer domesticus with high and low diversity of personality (exploratory behaviour), and found that their physiological state (body condition, physiological stress and oxidative damage) improved with increasing group-level diversity of personality. These findings demonstrate that group personality composition affects the condition of group members and individuals benefit from social heterosis (i.e. associating with a diverse set of behavioural types). This aspect of the social life can play a key role in affiliation rules of social animals and might explain the evolutionary coexistence of different personalities in nature.

中文翻译：

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具有不同性格的社会群体可以减轻鸣禽的生理压力


社会群体通常由不同的表型组成，包括人格类型，众所周知，这种多样性会影响整个群体的运作。社会选择理论提出，群体构成（即社会环境）也会影响个体群体成员的表现。然而，群体行为构成对群体成员的影响在很大程度上仍未被探索，而且个体在行为构成同质还是多样化的社会环境中是否受益更多仍然存在争议。我们通过实验形成了具有高和低人格多样性（探索行为）的麻雀群体，发现它们的生理状态（身体状况、生理应激和氧化损伤）随着群体水平人格多样性的增加而改善。这些发现表明，群体人格构成影响群体成员的状况，并且个体受益于社会杂种优势（即与多种行为类型相关联）。社会生活的这一方面可以在社会动物的隶属规则中发挥关键作用，并可能解释自然界中不同性格的进化共存。