Kaltwasser Laura, Mikac Una, Buško Vesna, Hildebrandt Andrea
Berlin School of Mind and Brain, Humboldt-Universität zu Berlin, Berlin, Germany.
Faculty of Humanities and Social Sciences, University of Zagreb, Zagreb, Croatia.
Front Behav Neurosci. 2017 Dec 20;11:250. doi: 10.3389/fnbeh.2017.00250. eCollection 2017.
Digit ratio (2D:4D) and facial width-to-height ratio (WHR) are supposedly static indicators of testosterone exposition during prenatal and pubertal lifetime, respectively. Both measures have been linked to aggressive and assertive behavior in laboratory economic games, as well as in real world scenarios. Most of the research-often limited to male subjects-considers the associations between these behaviors, traits, and hormonal markers separately for 2D:4D and WHR. Reported associations are weak and volatile. In the present study we had independent raters assess 2D:4D and WHR in a sample of = 175 participants who played the ultimatum game (UG). Respondent behavior in UG captures the tendency to reject unfair offers (negative reciprocity). If unfair UG offers are seen as provocations, then individuals with stronger testosterone exposition may be more prone to reject such offers. Economists argue that negative reciprocity reflects altruistic punishment, since the rejecting individual is sacrificing own resources. However, recent studies suggest that self-interest, in terms of status defense plays a substantial role in decisions to reject unfair offers. We also assessed social preferences by social value orientation and assertiveness via self-report. By applying structural equation modeling we estimated the latent level association of 2D:4D and WHR with negative reciprocity, assertiveness and prosociality in both sexes. Results revealed no robust association between any of the trait measures and hormonal markers. The measures of 2D:4D and WHR were not related with each other. Multigroup models based on sex suggested invariance of factor loadings allowing to compare hormone-behavior relationships of females and males. Only when collapsing across sex greater WHR was weakly associated with assertiveness, suggesting that individuals with wider faces tend to express greater status defense. Only the right hand 2D:4D was weakly associated with prosocial behavior, indicating that individuals with lower prenatal testosterone exposure are more cooperative. Rejection behavior in UG was not related with 2D:4D nor WHR in any of the models. There were also no curvilinear associations between 2D:4D and prosociality as theorized in the literature. Our results suggest that previous studies over-estimated the role of static markers of testosterone in accounting for aggression and competition behavior in males.
指长比（2D:4D）和面部宽高比（WHR）分别被认为是产前和青春期睾酮暴露的静态指标。在实验室经济游戏以及现实世界场景中，这两种测量方法都与攻击性和果断行为有关。大多数研究（通常仅限于男性受试者）分别考虑了2D:4D和WHR与这些行为、特征和激素标志物之间的关联。报告的关联较弱且不稳定。在本研究中，我们让独立评估者对175名参与最后通牒博弈（UG）的参与者样本进行2D:4D和WHR评估。UG中的受访者行为体现了拒绝不公平提议的倾向（负互惠）。如果不公平的UG提议被视为挑衅，那么睾酮暴露较强的个体可能更倾向于拒绝此类提议。经济学家认为，负互惠反映了利他惩罚，因为拒绝的个体在牺牲自己的资源。然而，最近的研究表明，就地位防御而言，自我利益在拒绝不公平提议的决策中起着重要作用。我们还通过社会价值取向评估了社会偏好，并通过自我报告评估了果断性。通过应用结构方程模型，我们估计了2D:4D和WHR与两性负互惠、果断性和亲社会行为之间的潜在关联水平。结果显示，任何特征测量与激素标志物之间均无显著关联。2D:4D和WHR的测量结果彼此无关。基于性别的多组模型表明因子载荷具有不变性，从而可以比较女性和男性的激素 - 行为关系。只有在合并性别后，较大的WHR才与果断性存在微弱关联，这表明脸较宽的个体往往表现出更强的地位防御。只有右手的2D:4D与亲社会行为存在微弱关联，这表明产前睾酮暴露较低的个体更具合作性。在任何模型中，UG中的拒绝行为均与2D:4D和WHR无关。文献中所推测的2D:4D与亲社会行为之间也不存在曲线关联。我们的结果表明，先前的研究高估了睾酮静态标志物在解释男性攻击和竞争行为中的作用。
