Hormonal underpinnings of status conflict: Testosterone and cortisol are related to decisions and satisfaction in the hawk-dove game

Examining the dual hormone hypothesis in wild male mountain gorillas (Gorilla beringei beringei)

The Challenge Hypothesis is an influential framework for understanding how androgens are involved in the promotion of competitive behavior during mating-related challenges and has been tested extensively in studies across scientific disciplines. Mixed support in psychological research led scholars to develop the Dual Hormone Hypothesis as a potential path forward, which argues that glucocorticoids moderate the relationship between androgens and status-striving. In the current study, we examine the Challenge Hypothesis and the Dual Hormone Hypothesis in wild male mountain gorillas, representing the first time the latter hypothesis has been tested in a non-human primate. In a sample of 30 adult males comprising over 600 days of observation, we find some limited support for the Challenge Hypothesis. Greater daily rates of targeted aggression toward other adult males corresponded to higher fecal androgen metabolites 1-2 days following observations, though this pattern did not fully generalize to dominance rank or other competitive behaviors examined. However, we find no support for the Dual Hormone Hypothesis: neither dominance rank nor any category of competitive behavior was predicted by the interaction between androgens and glucocorticoids. We close by discussing how this initial investigation might be leveraged toward the development of an expanded Dual Hormone Hypothesis that draws on the large evidence base in primate behavioral ecology.

Testosterone promotes dominance behaviors in the Ultimatum Game after players' status increases

Although testosterone is generally considered to promote dominance behaviors, in humans it fosters behaviors appropriate to achieving and maintaining social status, contingent upon the situation. Recent cross-sectional studies, such as Inoue et al. (Sci Rep 7:5335, 2017), have shown that dominance behaviors induced by testosterone are modulated by high status. Yet, it remains ambiguous whether a rise in social status within real-world social groups reshapes the relationship between testosterone and dominance behavior. To investigate this longitudinal question, we added a second wave to Inoue et al.'s study, collecting further data after an interval of 2 years. Members of a university rugby team that adheres to a rigid hierarchical order rooted in seniority played the Ultimatum Game with teammates and provided saliva for assays of testosterone and cortisol. Our analysis reveals that individuals with higher baseline salivary testosterone levels exhibited more dominance as their position in the hierarchy increased according to their seniority.

Revisiting the Relation Between Steroid Hormones and Unethicality in an Exploratory, Longitudinal Study With Female Participants

Research on the relation between hormones and unethical behaviors and tendencies has provided mixed results, hindering the understanding of the potential biological regulation of unethical behaviors and tendencies. We conducted an exploratory, longitudinal study (N = 257 women) allowing to estimate relations between, on the one hand, steroid hormones (testosterone, cortisol, estradiol, and progesterone) and conception probability and, on the other hand, a broad variety of measures related to unethicality (self-reported personality variables, cheating in committed relationships, self-serving economic dishonesty in a behavioral task, namely, the mind game). Contrary to theoretical assumptions of and results from some previous studies, we find no consistent relation between hormones and unethical behavior or tendencies in the majority of analyses. Yet, some small, exploratory associations emerged that call for (preregistered) replications, before more firm conclusions can be made.

No Compelling Evidence that Self-Reported Personality Traits Explain Basal Testosterone and Cortisol’s Associations with Status-Relevant Behavior

Objective

A goal of behavioral neuroendocrinology is to understand how basal hormone levels relate to behavior. Studies of human participants sometimes measure self-reported personality traits, in addition to or instead of direct behavioral observation. Although personality traits often predict their respective behaviors, whether personality explains hormone-behavior relationships remains unclear.

Methods

We obtained data from eight previous studies (total N = 985) that examined baseline testosterone and cortisol as predictors of status-relevant behavior (competitiveness, dominance, risk-taking, aggression, affiliation, and social status). We tested whether the previously reported hormone-behavior relationships are mediated by self-reported personality traits (e.g., trait dominance, prestige, extraversion). As a secondary research question, we also tested whether trait dominance moderated the testosterone-behavior relationships.

Results

As expected, self-reported personality traits often predicted status-relevant behaviors, but there was little evidence that traits also correlated with basal testosterone or the testosterone × cortisol interaction. Across all eight studies, personality traits did not significantly mediate hormone-behavior relationships. Indeed, the effect sizes of the hormone-behavior relationships were robust to the inclusion of personality traits as covariates. Further, we did not find strong or consistent evidence that trait dominance moderates the testosterone-behavior association.

Conclusion

Results suggest that basal testosterone and cortisol predict status-related behavior independent of self-reported personality. We discuss how these results may have broader implications for the physiological mechanisms by which testosterone and cortisol influence behavior, a process that could be unconscious and automatic. We also discuss alternative explanations, limitations, and future directions.

Narcissism moderates the association between basal testosterone and generosity in men

Research has linked hormones to behavioral outcomes in intricate ways, often moderated by psychological dispositions. The associations between testosterone and antisocial or prosocial outcomes also depend on dispositions relevant to status and dominance. In two studies (N1 = 68, N2 = 83), we investigated whether endogenous testosterone, measured in saliva, and narcissism, a psychological variable highly relevant to status motivation, interactively predicted men's preferences regarding resource allocation. Narcissism moderated the links between testosterone and social value orientation: among low narcissists testosterone negatively predicted generosity in resource allocation and probability of endorsing a prosocial (vs. pro-self) value orientation, whereas among high narcissists testosterone tended to positively predict generosity and the probability of endorsing a prosocial (vs. pro-self) value orientation. We discuss these results as examples of calibrating effects of testosterone on human behavior, serving to increase and maintain social status. We advocate the relevance of psychological dispositions, alongside situations, when examining the role of T in social outcomes.

Cortisol awakening response and testosterone jointly affect adolescents' theory of mind

Adolescence is a critical period for the maturation of neurobiological processes and hormone secretion. Recent studies on the dual-hormone hypothesis have indicated that basal cortisol and testosterone jointly affect dominant and aggressive behavior among adolescents and adults. Whether this hypothesis applies to prosocial-related understanding of others' mental states remains unclear. The present study investigated associations between basal testosterone, basal cortisol (and cortisol awakening response [CAR]), and the cognitive/affective theory of mind (ToM) in 243 adolescents (67.9 % male, aged 14 to 17 years, M_age = 16.09, standard deviation = 0.62). Cognitive ToM (cToM) and affective ToM (aToM) were assessed with a cartoon story reasoning task: In the cToM condition, participants viewed a comic strip story and needed to predict what would happen based on a character's intentions, and in the aToM condition, they viewed a comic strip of two characters interacting and needed to think about what would make the protagonist feel better. The results showed that basal testosterone and basal cortisol did not interact with each other to affect the performance of ToM, either in terms of ToM accuracy or response speed. However, under the condition of low CAR, testosterone is associated with the fast performance of cToM, although the interaction of testosterone and CAR occurred only in female adolescents. Overall, our data provide new evidence for the dual-hormone hypothesis and further extend the hypothesis to social understanding.

Exploring Finger Digit Ratios (2D:4D) in Surgeons, Professional Rugby Players, and Political Journalists to Form a Directional Hypothesis: Could Finger Length Predict Attention and Focus?

In this short report we explore the predictive nature of finger digit ratio (i.e., second/index finger length divided by fourth/ring finger length; 2D:4D) and achievement. This research, with niche and specialized populations, was intended to support and grow on knowledge obtained from other large population 2D:4D studies and help form a directional hypothesis for future work exploring finger digit ratio and “success.” Twenty-nine professional rugby players aged 25.1 ± 4.2 years, height 185.2 ± 6.3 cm and weight 101.9 ± 11.8 kg; n = 16 orthopedic surgeons aged 55.3 ± 9.3 years with height 183.8 ± 10.2 cm and weight 90.8 ± 14.0 kg; and n = 18 political journalists with age, height and weight of 38.8 ± 7.3 years, 182.8 ± 7.8 cm, and 84.4 ± 11.4 kg, respectively, were recruited. Three experiments were conducted where we (1) explored relationships for 2D:4D with testosterone and cortisol responsiveness to low stress exercise, (2) explored relationships for 2D:4D with pupil constriction and pupil constriction latency (pupillometry measures related to testosterone and cortisol responsiveness and to attentiveness), and (3) compared 2D:4D between rugby players, surgeons, and journalists. Our results revealed 2D:4D was not predictive of testosterone and cortisol responsiveness to low-level exercise stress. However, relationships exist for 2D:4D and pupillometry measures (p < 0.05). Journalists right minus left 2D:4D difference was significantly different to rugby players’ and surgeons (p < 0.05). We argue 2D:4D is likely predictive of testosterone sensitivity and associated ability to focus attention; a skill important to high achievement in various contexts.

Testosterone fluctuations in response to a democratic election predict partisan attitudes toward the elected leader

Intergroup competitions such as democratic elections can intensify intergroup polarization and conflict. Partisan attitudes toward the elected leader can also shift from before to after an election, but the biology underlying these attitudinal shifts remains largely unknown. An important factor could be the hormone testosterone, which is theorized to fluctuate during competition and to influence status seeking. In a naturalistic study of 113 registered voters, we measured changes in testosterone levels and attitudes toward the winner of the 2012 US Presidential Election. We found that supporters of the losing candidate (Mitt Romney) showed acute increases in testosterone levels compared to supporters of the winner (Barack Obama) on the evening of Election Day. Supporters of the losing candidate also demonstrated flatter diurnal testosterone slopes on Election Day that persisted up to two days after the election. Furthermore, greater increases in acute testosterone levels and flatter diurnal slopes among supporters of the losing candidate were associated with less positive evaluations of the winning candidate. These testosterone-moderated attitudinal shifts observed in the days after the election showed a directionally similar pattern with a weaker effect size six months later. Finally, we confirmed that the main results were robust to alternative data analytic choices using multiverse specification curve analysis. The findings from this paper suggest that hormonal responses to large-scale intergroup competitions may shape how we perceive our elected leaders, shedding light on the biology of intergroup relations.

Oxytocin moderates the association between testosterone-cortisol ratio and trustworthiness: A randomized placebo-controlled study

Oxytocin has been proposed to enhance feelings of trust, however, these findings have been difficult to replicate. Environmental or hormonal factors might influence this association. We studied whether oxytocin moderates the association between the testosterone-cortisol ratio, which is associated with risk taking behavior and aggression, and trustworthiness, while controlling for the general level of trust. A randomized double-blind placebo-controlled study with 53 healthy males was performed in which 32IU oxytocin (n = 27) or placebo (n = 26) was administered intranasally. Participants subsequently played the Trust Game in which they were allocated to the role of trustee. In the third phase of the Trust Game, we found a positive association between the testosterone-cortisol-ratio and the proportion of the amount that is returned to the investor (P=<0.01). However, administration of oxytocin reduced reciprocity in those with a high testosterone-cortisol ratio after reciprocity restoration (a significant interaction effect between administration of oxytocin and the testosterone-cortisol ratio in the third phase of the Trust Game, P = 0.015). The third phase of the Trust Game represents the restoration of reciprocity and trustworthiness, after this is violated in the second phase. Therefore, our data suggest that oxytocin might hinder the restoration of trustworthiness and diminish risk-taking behavior when trust is violated, especially in those who are hormonally prone to risk-taking behavior by a high testosterone-cortisol ratio.

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Oxytocin (32IU) was administered intranasally to healthy young males in a double-blind placebo-controlled study.

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Testosterone-cortisol ratio was positively associated with trustworthiness during the Trust Game.

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Oxytocin significantly attenuated the association between testosterone-cortisol ratio and trustworthiness.

Testosterone and cortisol are more predictive of choice behavior than a social nudge in adult males on a simple gift give-get task

Reproducibility of social research is ambitious, and evidence supporting this argument is increasing in psychology and social science research. This may be attributed to, in part, the high volume of qualitative research methodology used in social research along with difficulties in the reliability of measurement techniques. Therefore, use of more and better objective measures to complement existing techniques in social research are necessitated. To highlight this point we explored the success of give-get nudge in adults. Nudge being a subtle intervention to influence choice, without restricting choice. We also wanted to explore whether testosterone and cortisol, as objective psychophysiological markers, could explain nudge outcome. Participants were asked what they would like to get for Christmas, or what they would like to give. They were then presented with two chocolates, one big and one small, and instructed to take as a "reward" for their participation with the knowledge there was one other participant to take chocolate after them. It was hypothesized that those asked to give something for Christmas would take the smaller reward and vice versa. Salivary testosterone and cortisol were measured prior to, and 10 min after completing the exercise. The nature of the nudge itself did not predict behavior, but the hormone measures did. We speculate that testosterone may focus an individual on the nature of the question (nudge), while cortisol encourages self-focus. These results support the need to combine existing social research techniques with more objective markers.

The association between testosterone and unethical behaviours, and the moderating role of intrasexual competition

Researchers have called for a greater use of neuroscientific methods to advance theories in ethical behaviour. Our research takes a neuroscientific approach to investigating unethical behaviour by examining the roles of testosterone and intrasexual competition. We propose that unethical behavioural intentions will be greater for high-testosterone individuals in response to highly intrasexually competitive situations as a means of enhancing status. In an experiment, we measure baseline testosterone and assign participants to an intrasexually competitive or control condition. We demonstrate that in men, but not in women, testosterone is positively associated with unethical behavioural intentions in response to an intrasexual competition prime. Furthermore, using textual analysis, we find that testosterone is positively associated with the usage of anger-related words in response to an intrasexual competition prime among men. In turn, anger-related words are positively associated with unethical behaviour, suggesting that anger may play a role in motivating high-testosterone men to behave unethically. Overall, our findings contribute to the literature by suggesting that testosterone and competition lead to greater unethical behaviour in men, and that anger plays a role in promoting unethical behaviour.

Testing strategic pluralism: The roles of attractiveness and competitive abilities to understand conditionality in men's short-term reproductive strategies

The decision to allocate time and energy to find multiple sexual partners or raise children is a fundamental reproductive trade-off. The Strategic Pluralism Hypothesis argues that human reproductive strategies are facultatively calibrated towards either investing in mating or parenting (or a mixture), according to the expression of features dependent on the individual's condition. This study seeks to test predictions derived from this hypothesis in a sample of 242 young men (M ± SD = 22.12 ± 3.08) from Chile's 5th Region (33֯ south latitude). Specifically, two predictions were considered that raise questions about the relationship between traits related to physical and psychological attractiveness (fluctuating facial asymmetry and self-perception of attractiveness) and competitive skills (baseline testosterone and self-perception of fighting ability) with short-term reproductive strategies. Our results indicate that psychological features related to the self-perception of physical attractiveness are related to short-term reproductive strategies. However, no evidence was found that fluctuating facial asymmetry, basal levels of testosterone and self-perception of fighting ability were related to short-term reproductive strategies. These results support the existing evidence of the importance of physical attractiveness in calibrating men's reproductive strategies but cast doubts about the role of fluctuating facial asymmetry. They also suggest that traits related to physical attractiveness, in comparison to competitive capabilities, play a more important role in calibrating men's short-term reproductive strategies.

Beyond the challenge hypothesis: The emergence of the dual-hormone hypothesis and recommendations for future research

The challenge hypothesis makes specific predictions about the association between testosterone and status-seeking behaviors, but the findings linking testosterone to these behaviors are often inconsistent. The dual-hormone hypothesis was developed to help explain these inconsistencies. Specifically, according to this hypothesis, testosterone's association with status-seeking behavior depends on levels of cortisol. Here, we (1) describe the dual-hormone hypothesis in relation to the challenge hypothesis; (2) review recent studies that tested the dual-hormone hypothesis as well as meta-scientific evidence of heterogeneous dual-hormone findings across studies; (3) discuss potential explanations for this heterogeneity, including methodological considerations, contextual factors, and individual differences; and (4) provide recommendations for new work aimed at testing and extending the dual-hormone hypothesis.

Honest Signals of Status: Facial and Bodily Dominance Are Related to Success in Physical but Not Nonphysical Competition

Recent studies suggest that both facial and bodily dominance promote high status positions and predict status-seeking behaviors such as aggression and social dominance. An evolutionarily relevant context in which associations between these dominance signals and status outcomes may be prevalent are face-to-face status contests. The present study examined whether facial and bodily dominance predicted success in dyadic competitions (one physical discipline, arm wrestling, and three nonphysical disciplines) in men (N = 125) in a controlled laboratory setting. Men's bodies and faces were independently rated for physical dominance, and associations of these ratings with contest outcomes as well as mediating and moderating variables (such as physical strength, body height, trait dominance, baseline and reactive testosterone) were examined. Both facial and bodily dominance positively predicted success in the physical discipline, mediated by physical strength, but not in the three nonphysical disciplines. Our findings demonstrate that facial and bodily physical dominance may be honest signals for men's formidability and hence status potential, at least in a physically competitive context.

Within- and between-person variation in morning testosterone is associated with economic risk-related decisions in athletic women across the menstrual cycle

Literature suggests that women experience ovulatory shifts in risk-taking behaviours across different domains, which might be partly attributed to changes in testosterone (T). Thus, we investigated associations between menstrual variability in T concentrations and economic risk-related decisions among athletic women. Thirty-five women were monitored across three consecutive menstrual cycles. Testing occurred on day seven (D7), 14 (D14) and 21 (D21) following the onset of menses. The morning (7 to 8 am) assessment of salivary T (sal-T) and cortisol (sal-C) was followed by the economic Hawk-Dove game (11 am to 12 pm) played in pairs, where hawk decisions were used to index risk. Morning sal-T concentration increased from D7 to D14, before decreasing on D21 (p < 0.001), representing moderate effect size (ES) changes of 0.6 to 0.8. Morning sal-C did not vary over time. Hawk choices paralleled the sal-T results, being elevated on D14 (p < 0.001) with large ES changes of 1.8. Regression analyses revealed that morning sal-T concentration was positively related (p ≤ 0.01) to the number of hawks chosen between- (beta = 0.47) and within-participants (beta = 0.10) when controlling for training hours and menstrual day. In summary, the risk-related choices of athletic women during a dyadic contest covaried with morning sal-T concentrations across the menstrual cycle. Both outcomes were positively correlated on a within- and between-person level. Confirming the major sources of T variation across the menstrual cycle, whilst discerning its relationship with other risk-related behaviours, would be worthwhile avenues for research.

Testosterone, cortisol, and status-striving personality features: A review and empirical evaluation of the Dual Hormone hypothesis

Decades of research in behavioral endocrinology has implicated the gonadal hormone testosterone in the regulation of mating effort, often expressed in primates in the form of aggressive and/or status-striving behavior. Based on the idea that neuroendocrine axes influence each other, recent work among humans has proposed that links between testosterone and indices of status-striving are rendered conditional by the effects of glucocorticoids. The Dual Hormone hypothesis is one particular instance of this argument, predicting that cortisol blocks the effects of testosterone on dominance, aggression, and risk-taking in humans. Support for the Dual Hormone hypothesis is wide-ranging, but considerations of theoretical ambiguity, null findings, and low statistical power pose problems for interpreting the published literature. Here, we contribute to the development of the Dual Hormone hypothesis by (1) critically reviewing the extant literature-including p-curve analyses of published findings; and, (2) "opening the file drawer" and examining relationships between testosterone, cortisol, and status-striving personality features in seven previously published studies from our laboratories (total N = 718; median N per feature = 318) that examined unrelated predictions. Results from p-curve suggest that published studies have only 16% power to detect effects, while our own data show no robust interactions between testosterone and cortisol in predicting status-striving personality features. We discuss the implications of these results for the Dual Hormone hypothesis, limitations of our analyses, and the development of future research.

Basal testosterone's relationship with dictator game decision-making depends on cortisol reactivity to acute stress: A dual-hormone perspective on dominant behavior during resource allocation

The dual-hormone hypothesis proposes that testosterone's relationship with status-seeking behavior is moderated by cortisol. However, research testing this hypothesis has focused on basal cortisol; the potential moderating effect of the acute cortisol response to stress has been largely overlooked. The present research investigated the moderating role of cortisol responses to an acute stressor on basal testosterone's link with dominant, status-relevant decision-making. Also, given the multifaceted nature of the response to acute stress, cardiovascular and affective responses to the stressor were examined as alternative moderators of the testosterone-behavior relationship. Participants (N = 112; 56% female) were exposed to a social-evaluative stressor, and their stress responses were measured. Participants subsequently engaged in a one-shot dictator game, wherein they were asked to split money ($10) with a confederate counterpart. The amount of money participants decided to keep for themselves was treated as a metric of dominant status-seeking behavior. For individuals who demonstrated lower cortisol responses to the stressor, basal testosterone was positively associated with more dominant behavior (i.e., keeping more money for oneself), but for those who showed higher cortisol responses, the testosterone-behavior relationship was suppressed. Moreover, other aspects of the stress response (i.e., cardiovascular and affective responses) did not moderate the relationship between basal testosterone and dictator game behavior. These results provide unique support for the dual-hormone hypothesis using markers of stress-induced cortisol change. The findings also suggest that the antagonistic effects of stress on testosterone's role in motivating status-relevant behavior may be specific to cortisol's role in the acute stress response.

Human social neuroendocrinology: Review of the rapid effects of testosterone

Contribution to Special Issue on Fast effects of steroids. It is well documented that testosterone concentrations change rapidly within reproductively relevant contexts (e.g., competition, mate-seeking). It has been argued that such rapid changes in testosterone may serve to adaptively fine-tune ongoing and/or future social behaviour according to one's social environment. In this paper, we review human correlational and experimental evidence suggesting that testosterone fluctuates rapidly in response to competition and mate-seeking cues, and that such acute changes may serve to modulate ongoing and/or future social behaviours (e.g., risk-taking, competitiveness, mate-seeking, and aggression). Some methodological details, which limit interpretation of some of this human work, are also discussed. We conclude with a new integrative model of testosterone secretion and behaviour, the Fitness Model of Testosterone Dynamics. Although we focus primarily on human aggression in this review, we also highlight research on risk-taking, competitiveness, and mate-seeking behaviour.

Testosterone, Cortisol and Financial Risk-Taking

Both testosterone and cortisol have major actions on financial decision-making closely related to their primary biological functions, reproductive success and response to stress, respectively. Financial risk-taking represents a particular example of strategic decisions made in the context of choice under conditions of uncertainty. Such decisions have multiple components, and this article considers how much we know of how either hormone affects risk-appetite, reward value, information processing and estimation of the costs and benefits of potential success or failure, both personal and social. It also considers how far we can map these actions on neural mechanisms underlying risk appetite and decision-making, with particular reference to areas of the brain concerned in either cognitive or emotional functions.

Hormone-Diversity Fit: Collective Testosterone Moderates the Effect of Diversity on Group Performance

Prior research has found inconsistent effects of diversity on group performance. The present research identifies hormonal factors as a critical moderator of the diversity-performance connection. Integrating the diversity, status, and hormone literatures, we predicted that groups collectively low in testosterone, which orients individuals less toward status competitions and more toward cooperation, would excel with greater group diversity. In contrast, groups collectively high in testosterone, which is associated with a heightened status drive, would be derailed by diversity. Analysis of 74 randomly assigned groups engaged in a group decision-making exercise provided support for these hypotheses. The findings suggest that diversity is beneficial for performance, but only if group-level testosterone is low; diversity has a negative effect on performance if group-level testosterone is high. Too much collective testosterone maximizes the pains and minimizes the gains from diversity.