Androgens, traditionally viewed as hormones that regulate secondary sexual characteristics and reproduction in male vertebrates, are often modulated by social stimuli. High levels of the 'social hormone' testosterone (T) are linked to aggression, dominance, and competition. Low T levels, in contrast, promote sociopositive behaviours such as affiliation, social tolerance, and cooperation, which can be crucial for group-level, collective behaviours. Here, we test the hypothesis that - in a collective context - low T levels should be favourable, using non-reproductive male and female stickleback fish (Gasterosteus aculeatus) and non-invasive waterborne hormone analysis. In line with our predictions, we show that the fishes' T levels were significantly lower during shoaling compared to when alone, with high-T individuals showing the largest decrease. Ruling out stress-induced T suppression and increased T conversion into oestradiol, we find evidence that shoaling directly affects androgen responsiveness. We also show that groups characterized by lower mean T exhibit less hierarchical leader-follower dynamics, suggesting that low T promotes egalitarianism. Overall, we show that collective action results in lower T levels, which may serve to promote coordination and group performance. Our study, together with recent complementary findings in humans, emphasizes the importance of low T for the expression of sociopositive behaviour across vertebrates, suggesting similarities in endocrine mechanisms.

中文翻译：

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集体行动降低了雄激素的响应能力，暗示了stick鱼中的浅滩动态。

雄激素通常被认为是调节雄性脊椎动物继发性特征和繁殖的激素，通常受到社会刺激的调节。高水平的“社会激素”睾丸激素（T）与侵略性，统治力和竞争息息相关。相反，低T水平会促进社交积极行为，例如从属关系，社会宽容和合作，这对于群体层面的集体行为至关重要。在这里，我们测试了这样一个假设：在总体情况下，使用非生殖雄性和雌性le鱼（Gasterosteus aculeatus）和非侵入性水生激素分析，在较低的水平下应该有利于低T水平。与我们的预测相符，我们显示，与单独饲养相比，浅滩捕捞过程中鱼类的T含量显着降低，高T个体的下降幅度最大。排除压力诱导的T抑制和增加的T向雌二醇的转化率，我们发现浅滩直接影响雄激素响应的证据。我们还表明，以较低的平均T为特征的群体表现出较少的等级领导者跟随者动态，这表明较低的T促进了平等主义。总体而言，我们表明集体行动会导致较低的T水平，这可能有助于促进协调和小组绩效。我们的研究以及最近在人类中的补充发现，强调了低T对于在整个脊椎动物中表达社会阳性行为的重要性，表明内分泌机制相似。我们发现浅滩直接影响雄激素反应的证据。我们还表明，以较低的平均T为特征的群体表现出较少的等级领导者跟随者动态，这表明较低的T促进了平等主义。总体而言，我们表明集体行动会导致较低的T水平，这可能有助于促进协调和小组绩效。我们的研究以及最近在人类中的补充发现，强调了低T对于在整个脊椎动物中表达社会阳性行为的重要性，表明内分泌机制相似。我们发现浅滩直接影响雄激素反应的证据。我们还表明，以较低的平均T为特征的群体表现出较少的等级领导者跟随者动态，这表明较低的T促进了平等主义。总体而言，我们表明集体行动会导致较低的T水平，这可能有助于促进协调和小组绩效。我们的研究以及最近在人类中的补充发现，强调了低T对于在整个脊椎动物中表达社会阳性行为的重要性，表明内分泌机制相似。这可能有助于促进协调和小组绩效。我们的研究以及最近在人类中的补充发现，强调了低T对于在整个脊椎动物中表达社会阳性行为的重要性，表明内分泌机制相似。这可能有助于促进协调和小组绩效。我们的研究以及最近在人类中的补充发现，强调了低T对于在整个脊椎动物中表达社会阳性行为的重要性，表明内分泌机制相似。