Goette Lorenz, Bendahan Samuel, Thoresen John, Hollis Fiona, Sandi Carmen
Department of Economics, Faculty of Business and Economics, University of Lausanne (UNIL), CH-1015 Lausanne, Switzerland.
Laboratory of Behavioral Genetics, Brain Mind Institute, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
Psychoneuroendocrinology. 2015 Apr;54:115-23. doi: 10.1016/j.psyneuen.2015.01.019. Epub 2015 Feb 19.
Social competition is a fundamental mechanism of evolution and plays a central role in structuring individual interactions and communities. Little is known about the factors that affect individuals' competitive success, particularly in humans. Key factors might include stress, a major evolutionary pressure that can affect the establishment of social hierarchies in animals, and individuals' trait anxiety, which largely determines susceptibility to stress and constitutes an important determinant of differences in competitive outcomes. Using an economic-choice experiment to assess competitive self-confidence in 229 human subjects we found that, whereas competitive self-confidence is unaffected by an individual's anxiety level in control conditions, exposure to the Trier social stress test for groups drives the behavior of individuals apart: low-anxiety individuals become overconfident, and high-anxiety individuals become underconfident. Cortisol responses to stress were found to relate to self-confidence, with the direction of the effects depending on trait anxiety. Our findings identify stress as a major regulator of individuals' competitiveness, affecting self-confidence in opposite directions in high and low anxious individuals. Therefore, our findings imply that stress may provide a new channel for generating social and economic inequality and, thus, not only be a consequence, but also a cause of inequality through its impact on competitive self-confidence and decision making in financially-relevant situations.
社会竞争是进化的基本机制，在构建个体互动和群体方面发挥着核心作用。对于影响个体竞争成功的因素，尤其是在人类中，我们所知甚少。关键因素可能包括压力，这是一种主要的进化压力，会影响动物社会等级制度的建立，以及个体的特质焦虑，它在很大程度上决定了对压力的易感性，并构成竞争结果差异的一个重要决定因素。通过一项经济选择实验来评估229名人类受试者的竞争自信心，我们发现，在对照条件下，竞争自信心不受个体焦虑水平的影响，但让群体接受特里尔社会压力测试会使个体行为产生分化：低焦虑个体变得过度自信，而高焦虑个体则变得信心不足。研究发现，皮质醇对压力的反应与自信心有关，其影响方向取决于特质焦虑。我们的研究结果表明，压力是个体竞争力的主要调节因素，对高焦虑和低焦虑个体的自信心产生相反方向的影响。因此，我们的研究结果意味着，压力可能为产生社会和经济不平等提供一个新渠道，因此，它不仅是不平等的一个后果，而且通过其对与财务相关情况下的竞争自信心和决策的影响，也是不平等的一个原因。
