No Robust Association between Static Markers of Testosterone and Facets of Socio-Economic Decision Making.

Laura Kaltwasser,Una Mikac,Vesna Buško,Andrea Hildebrandt

doi:10.3389/fnbeh.2017.00250

Abstract

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 N = 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.

Highlights

The Impact of TestosteroneThe steroid hormone testosterone, produced in the male testes, and to a lesser extent in female ovaries, circulates the human brain throughout life and it is assumed to impact behavior and its development
If unfair ultimatum game (UG) offers are seen as provocations, individuals with stronger prenatal testosterone exposition may be more prone to reject such offers
We run a series of measurement and structural models including latent variables representing organizational effects of hormones measured by estimations of (1) 2D:4D provided by two different raters and (2) of width-to-height ratio (WHR) estimated by two raters as well

Summary

Introduction

The Impact of TestosteroneThe steroid hormone testosterone, produced in the male testes, and to a lesser extent in female ovaries, circulates the human brain throughout life and it is assumed to impact behavior and its development. Endocrines have been shown to affect attachment and sex (Carter, 1998; Insel and Young, 2001), aggression (Koolhaas et al, 1990; Dabbs et al, 1995) and social status (Mazur and Booth, 1998; Josephs et al, 2003). Sexual behavior, competition for status or fighting can alter endocrine levels (Mazur and Lamb, 1980; Elias, 1981; Carmichael et al, 1994). Previous research in primates and humans suggests that high levels of testosterone promote behaviors intended to enhance one’s status over other individuals and to climb up the social hierarchy. An individual is dominant if its intent is to gain or defend high status over another member of its species. The distinction between dominance and aggression is important in humans, where dominance is often asserted without any intent to cause injury. Ehrenkranz et al (1974) showed that both, aggressive prisoners and dominant, but non-aggressive prisoners had a significantly higher level of plasma testosterone as compared with non-aggressive and low dominance prisoners

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