Behavioral Endocrinology Laboratory, Department of Psychology, Simon Fraser University, Burnaby, Canada.
PLoS One. 2013;8(1):e52582. doi: 10.1371/journal.pone.0052582. Epub 2013 Jan 9.
Dominance contests are recurrent and widespread causes of stress among mammals. Studies of activation of the stress axis in social defeat - as reflected in levels of adrenal glucocorticoid, cortisol - have generated scattered and sometimes contradictory results, suggesting that biopsychological individual differences might play an important mediating role, at least in humans. In the context of a larger study of the regulation of endocrine responses to competition, we evaluated the notion that mood states, such as self-assurance and hostility, may influence cortisol reactivity to dominance cues via an interplay with baseline testosterone, considered as a potential marker of individual differences in dominance. Seventy healthy male university students (mean age 20.02, range 18-26) provided saliva samples before and after competing for fifteen minutes on a rigged computer task. After a winner was determined, all participants were assessed on their mood states through a standardized psychometric instrument (PANAS-X). Among winners of a rigged videogame competition, we found a significant interaction between testosterone and self-assurance in relation to post-competition cortisol. Specifically, self-assurance was associated with lower post-competition cortisol in subjects with high baseline testosterone levels, but no such relationship was observed in subjects with lower baseline testosterone levels. In losers of the competition no interaction effect between basal testosterone and hostility was observed. However, in this subgroup a significant negative relationship between basal testosterone and post-competition cortisol was evident. Overall, these findings provide initial support for the novel hypothesis that biological motivational predispositions (i.e. basal testosterone) and state (i.e. mood changes) may interact in regulating the hypothalamic-pituitary-adrenal axis activation after a social contest.
支配地位竞争是哺乳动物中反复出现且广泛存在的应激源。研究表明，社会挫败（表现为肾上腺糖皮质激素皮质醇水平升高）会激活应激轴，这一研究结果参差不齐，有时甚至相互矛盾，这表明生物心理个体差异可能发挥着重要的调节作用，至少在人类中是这样。在一项关于内分泌对竞争反应调节的更大规模研究中，我们评估了这样一种观点，即情绪状态（如自信和敌意）可能通过与基础睾酮的相互作用影响皮质醇对支配线索的反应，而基础睾酮被认为是个体支配差异的潜在标志物。70 名健康的男性大学生（平均年龄 20.02 岁，范围 18-26 岁）在参加一个设定好的计算机任务竞争前 15 分钟提供唾液样本。确定获胜者后，所有参与者通过标准化心理计量工具（PANAS-X）评估他们的情绪状态。在一场设定好的电子游戏比赛的获胜者中，我们发现基础睾酮和自信之间存在与比赛后皮质醇相关的显著交互作用。具体来说，在基础睾酮水平较高的受试者中，自信与比赛后皮质醇水平较低相关，但在基础睾酮水平较低的受试者中则没有这种关系。在比赛的失败者中，基础睾酮和敌意之间没有观察到交互作用。然而，在这个亚组中，基础睾酮与比赛后皮质醇之间存在显著的负相关关系。总的来说，这些发现初步支持了一个新的假设，即生物动机倾向（即基础睾酮）和状态（即情绪变化）可能相互作用，调节下丘脑-垂体-肾上腺轴在社会竞争后的激活。
