Zilioli Samuele, Watson Neil V
Behavioral Endocrinology Laboratory, Department of Psychology, Simon Fraser University, Canada.
Behavioral Endocrinology Laboratory, Department of Psychology, Simon Fraser University, Canada.
Psychoneuroendocrinology. 2014 Sep;47:1-9. doi: 10.1016/j.psyneuen.2014.05.001. Epub 2014 May 10.
In many species testosterone fluctuates in concert with outcome-dependent changes in social status, such that winning a competition leads to an increase in circulating testosterone (i.e., competition effect). Although this phenomenon has been well studied in humans, the cumulative endocrine impact of multiple successive competitions is poorly understood. Moreover, although changes in testosterone after a competition seem to predict immediate aggressive behavior, competitive motivation, risk-taking, and affiliation, whether this endocrine response also has long-term behavioral effects, as suggested by studies in non-human animals, has not been examined. In this study, salivary testosterone was collected from pairs of male participants engaging, on two consecutive days, in head-to-head competitions on a previously validated laboratory task. We found that testosterone reactivity on the first day, which was congruent with the competition effect (i.e., net testosterone increase in randomly assigned winners), predicted the task performance on the second day. Further, when looking at testosterone reactivity on the second day, those individuals that lost both competitions experienced the steepest decline in testosterone compared to those individuals who lost on the second day but won on the first day. Testosterone fluctuations on the second day were also analyzed considering the type of status hierarchy (stable vs. unstable) that emerged as a result of the combined outcomes of the two competitions. In accordance with the challenge hypothesis, men in unstable hierarchies (first day winners/second day losers and first day losers/second day winners) experienced an increase in testosterone compared to men in the stable hierarchies (double winners and double losers). Results are discussed within a comparative perspective, drawing parallels with the winner effect and the challenge hypothesis observed in non-human animals.
在许多物种中，睾酮水平会随着社会地位依赖于结果的变化而同步波动，以至于赢得一场竞争会导致循环睾酮水平升高（即竞争效应）。尽管这种现象在人类中已得到充分研究，但多次连续竞争对内分泌的累积影响却知之甚少。此外，尽管竞争后睾酮水平的变化似乎可以预测即时的攻击行为、竞争动机、冒险行为和社交行为，但这种内分泌反应是否也像在非人类动物研究中所表明的那样具有长期行为影响，尚未得到检验。在本研究中，从成对的男性参与者那里收集唾液睾酮，这些参与者在连续两天参与一项先前经过验证的实验室任务中的面对面竞争。我们发现，第一天的睾酮反应性与竞争效应一致（即随机分配的获胜者的净睾酮增加），预测了第二天的任务表现。此外，在观察第二天的睾酮反应性时，与那些第一天获胜但第二天失败的个体相比，两场竞争都失败的个体睾酮水平下降最为显著。还根据两场竞争综合结果所形成的地位等级类型（稳定型与不稳定型）对第二天的睾酮波动进行了分析。与挑战假说一致，与处于稳定等级（双胜和双败）的男性相比，处于不稳定等级（第一天获胜/第二天失败和第一天失败/第二天获胜）的男性睾酮水平有所升高。研究结果将在比较的视角下进行讨论，与在非人类动物中观察到的胜者效应和挑战假说进行类比。
