Thus, it is not surprising that the meta-analysis found substantial heterogeneity both between and within categories of behavior. Researchers should consider using liquid chromatography tandem mass spectrometry (LC-MS/MS) to improve the accuracy of hormone measurement. Moreover, if studies and findings are published as registered reports – i.e., preregistrations that are peer-reviewed and provisionally accepted prior to data collection – then these practices should also help to reduce publication bias (Nosek & Lakens, 2014). Prior to data analysis (and preferably, prior to data collection), researchers should describe their intended analytical approach for hormones – e.g., using basal or dynamic measures, defining outliers, exclusion criteria for participation, and so on. In a paper published five years ago, researchers ran two lab studies on grad students. That’s the message of a new study published in the Journal of Personality and Social Psychology. Carlyle's 1840 "Great Man theory", which emphasized the role of leading individuals, met opposition (from Herbert Spencer, Leo Tolstoy, and others) in the 19th and 20th centuries. Group members tend to be more contented and productive when they have a leader to guide them. This "need for a leader" becomes especially strong in troubled groups that are experiencing some sort of conflict. We therefore suggested that the hyraxes' riskiest move is that of their arrival at a feeding location17. Bachelors live mostly solitarily on the periphery of the colonies, do not participate in coordinated group activities (Fig. S1), and their interaction with the mixed-sex groups is mainly for mating15. A hyrax group usually comprises of one mature resident male and 3–20 females over 2 years of age with their pups. Cortisol is released when individuals experience challenging or energetically demanding situations, and it mediates the metabolic and physiological responses resulting from the hypothalamic–pituitary–adrenal (HPA) axis activation. Although a significant body of research has examined the effects of exogenously administered testosterone or cortisol on social behavior, to date no study has reported the behavioral effects of simultaneous pharmacological manipulation of both hormones. The dual-hormone profiles of high testosterone levels coupled with lower or higher cortisol levels may be related to status-seeking behavior via different mechanisms. Although the connection between specific behaviors and perceptions of social status were clear in some dual-hormone studies (e.g. ratings of "leader-like" were correlated with observed behaviors such as assertiveness, confidence, and decisiveness in Mehta & Josephs, 2010), in other studies it remains unclear whether the behavioral outcome measure was relevant to status. Seven judges rated video recordings of these social interactions on dominant leadership behaviors, defined as an assertive and self-assured behavioral style (Anderson & Kilduff, 2009). The statistical prediction of this hypothesis is a negative testosterone × cortisol interaction term, when higher scores on the outcome measure indicate increases in behaviors related to the pursuit of high status. Thus, previous studies that tested the challenge hypothesis may have found weak or null results because they did not consider cortisol as a potential moderator of testosterone’s association with behaviors linked to status. Testosterone, which plays a role in enabling leadership skills, can be adversely affected by high levels of stress hormone cortisol. These two studies suggest that cues to an opponent’s status may be critical moderators of the testosterone × cortisol interaction and may explain some of the heterogeneity in previous dual-hormone findings. This argument suggests that elevated testosterone should be related to increased status-seeking behavior against high-status opponents, but only when cortisol levels are low; in a reversal of this pattern, elevated testosterone should be related to increased status-seeking behavior against lower-status opponents when cortisol levels are high. In contrast, the pairing of high concern for status (high testosterone) with high stress (high cortisol) may be related to enhanced social threat, resulting in avoiding higher-status opponents and engaging in competitive behavior with lower-status opponents instead. High concern for status (high testosterone) and low stress (low cortisol) may specifically direct behaviors targeted towards challenging higher-status opponents as a means to rise in the hierarchy. In laissez-faire or free-rein leadership, decision-making is passed on to the subordinates. Under the autocratic leadership style, all decision-making powers are centralized in the leader, as with dictators. A field in which leadership style has gained attention is that of military science, which expresses a holistic and integrated view of leadership, including how a leader's physical presence determines how others perceive that leader. A leadership style is a leader's way of providing direction, implementing plans, and motivating people. Here we found that testosterone and cortisol interaction predicted leadership status that involves risk-taking in rock hyraxes, a finding that provides strong support for the DHH. The original dual-hormone hypothesis suggested that high testosterone levels predicted higher social status only when cortisol levels were low6. Following the DHH predictions, we hypothesized that cortisol and testosterone would interact to predict behaviors related to leadership that involves risk, depending on the context. In this work we examined the association of long-term, integrated testosterone and cortisol levels with leadership in the rock hyrax (Procavia capensis), a social mammal that maintains long-term associations in stable social groups12. Testosterone too has a well-established role in risk-taking behavior, and the dual-hormone hypothesis posits that the interaction of testosterone and cortisol can predict social behavior. In response to the early criticisms of the trait approach, theorists began to research leadership as a set of behaviors by evaluating the behavior of successful leaders, determining a behavior taxonomy, and identifying broad leadership styles. Studies of leadership have produced theories involving (for example) traits, complexity, collective intelligence, situational interaction,function, behavior, power, vision, values, charisma, and intelligence,among others. While testosterone promotes dominance and risk-taking, high levels of cortisol due to stress can hinder these qualities. However, the balance between testosterone and cortisol is essential in maintaining optimal leadership qualities. Moreover, chronic stress can disrupt the delicate balance of hormones in the body, including testosterone and cortisol. The delicate interplay between testosterone and other hormones highlights the importance of hormone balance in leadership development. This highlights the significance of stress reduction techniques such as yoga and meditation, which can help unleash the leadership potential in individuals. An important direction for future dual-hormone research will be to more explicitly determine when testosterone × cortisol interaction effects may be seen with baseline hormone levels versus dynamic hormonal responses. One recent report has highlighted the specificity of endogenous cortisol’s moderating influence - and not cardiovascular indices of stress responses - on the link between testosterone and status seeking (Prasad, Knight, and Mehta, 2019). Overall, this work suggests testosterone may heighten the rewarding or threatening properties of a given status-relevant situation, dependent on cortisol levels. For an individual with high testosterone and low cortisol levels, the threat inherent to a higher-status opponent may not be as salient and, as discussed above, the potential reward from competing with a higher-status opponent perhaps is more persuasive. In line with this reasoning, one recent study found that high basal testosterone was positively related to a psychological measure of reward (enjoyment of a status-relevant economic game, the hawk-dove game), but only among low-cortisol but not high-cortisol individuals (Mehta et al., 2017). Testosterone treatment in males who had high (endogenous) cortisol levels resulted in more competitive behavior against prior losers (lower-status opponents) and avoided prior winners (higher-status opponents).
