Samuele Zilioli

Testosterone and cortisol jointly modulate risk-taking

Recent theories propose that testosterone should be positively related to risk-taking, but empirical support is mixed. Building on the dual-hormone hypothesis, the present research tested whether testosterones role in risk-taking depends on cortisol. Study 1 (N=115) tested this hypothesis in a mixed-sex sample with self and informant reports of risk-taking. Study 2 (N=165) tested this hypothesis in a male-only sample with the Balloon Analog Risk Task, a behavioral measure of risk-taking. Across both studies, there was a positive association between basal testosterone and risk-taking among individuals low in basal cortisol but not individuals high in basal cortisol. This pattern emerged in both males and females and across multiple measures of risk-taking (self reports, informant reports, behavior). These studies provide novel empirical support for the claim that testosterone and cortisol jointly regulate risk-taking. Discussion focuses on putative mechanisms as well as implications for real-world risk-taking behaviors.

Purpose in life predicts allostatic load ten years later

OBJECTIVE Living a purposeful life is associated with better mental and physical health, including longevity. Accumulating evidence shows that these associations might be explained by the association between life purpose and regulation of physiological systems involved in the stress response. The aim of this study was to investigate the prospective associations between life purpose and allostatic load over a 10-year period. METHODS Analyses were conducted using data from the Midlife in the United States (MIDUS) survey. Assessment of life purpose, psychological covariates and demographics were obtained at baseline, while biomarkers of allostatic load were assessed at the 10-year follow-up. RESULTS We found that greater life purpose predicted lower levels of allostatic load at follow-up, even when controlling for other aspects of psychological well-being potentially associated with allostatic load. Further, life purpose was also a strong predictor of individual differences in self-health locus of control-i.e., beliefs about how much influence individuals can exert on their own health-which, in turn, partially mediated the association between purpose and allostatic load. Although life purpose was also negatively linked to other-health locus of control-i.e., the extent to which individuals believe their health is controlled by others/chance-this association did not mediate the impact of life purpose on allostatic load. CONCLUSION The current study provides the first empirical evidence for the long-term physiological correlates of life purpose and supports the hypothesis that self-health locus of control acts as one proximal psychological mechanism through which life purpose may be linked to positive biological outcomes.

Functional significance of men’s testosterone reactivity to social stimuli

Rapid testosterone fluctuations in response to social stimuli are observed across a wide range of species, and the highly conserved nature of these fluctuations suggests an adaptive function. This paper reviews the current literature on testosterone reactivity, primarily in human males, and illustrates how life-history theory provides an adequate theoretical framework to interpret findings. The review is structured around supporting evidence suggesting that situations implicated in mating effort either directly (e.g., interactions with a mate) or indirectly (e.g., intrasexual competition) are generally associated with a brief elevation of testosterone, while situations implicated in parenting effort (e.g., nurturant interactions with offspring) are generally associated with a decline in testosterone. Further, we discuss how these fluctuations in testosterone have been linked to future behaviors, and how situational, motivational, and physiological variables moderate the interplay between social stimuli, testosterone reactivity, and behavior. Supporting the notion that testosterone can play a causal role in modulating behavior in response to social stimuli, we also summarize recent single administration studies examining the effects of testosterone on physiology, neurobiology, and behavior. A conceptual model provides links between supported findings, and hypothesized pathways requiring future testing.

Social network centrality and hormones: The interaction of testosterone and cortisol

In this study we tested whether testosterone and cortisol interacted in predicting social network centrality within a male rugby team. Using social network analysis (SNA), three measures of centrality were investigated: popularity (i.e., the number of incoming ties a participant receives), gregariousness (i.e., the number of ties leaving from a participant and reaching out to others), and betweenness (i.e., the number of times a person lies between two other individuals). In line with the idea that testosterone and cortisol jointly regulate the emergence of social status, we found that individuals with high basal testosterone and low basal cortisol were more popular and more likely to act as connectors among other individuals (i.e., betweenness). The same hormonal profile was not predictive of gregariousness. However, in line with the small literature on the topic, we found that cortisol was inversely correlated with gregariousness. Despite the cross-sectional and correlational nature of our research design, these findings represent the first empirical evidence that testosterone and cortisol interact to predict complex measures of social hierarchy position derived from social network analyses.

Interest in Babies Negatively Predicts Testosterone Responses to Sexual Visual Stimuli Among Heterosexual Young Men

Men’s testosterone may be an important physiological mechanism mediating motivational and behavioral aspects of the mating/parenting trade-off not only over time but also in terms of stable differences between mating-oriented and parenting-oriented individuals. In this study, we tested the hypothesis that self-reported interest in babies is inversely related to testosterone reactivity to cues of short-term mating among heterosexual young men. Among 100 participants, interest in babies was related to a slow life-history strategy, as assessed by the Mini-K questionnaire, and negatively related to testosterone responses to an erotic video. Interest in babies was not associated with baseline testosterone levels or with testosterone reactivity to nonsexual social stimuli. These results provide the first evidence that differential testosterone reactivity to sexual stimuli may be an important aspect of individual differences in life-history strategies among human males.

Comparison of clear and narrow outcomes on testosterone levels in social competition.

Abstract A contribution to a special issue on Hormones and Human Competition. Social competition is associated with marked emotional, behavioral and hormonal responses, including changes in testosterone levels. The strength and direction of these responses is often modulated by levels of other hormones (e.g. cortisol) and depends on psychological factors – classically, the objective outcome of a competition (win vs. loss) but also, hypothetically, the closeness of that outcome (e.g. decisive victory vs. close victory). We manipulated these two aspects of a social contest among male participants (N = 166), to investigate how testosterone and affect fluctuated as a function of clear vs. narrow wins and clear vs. narrow losses. We found that losing a competition by a small margin (a narrow loss) was experienced as more pleasant than a clear loss. Among individuals with higher levels of basal cortisol, winning the competition by a narrow margin was associated with a decrease in testosterone levels. These findings are discussed within the framework of the status instability hypothesis and the growing literature on how situational and physiological factors modulate testosterone reactivity to social contests. HighlightsA competition task was developed to compare clear/narrow victories and defeats.Narrow victories reduced testosterone among individuals with higher basal cortisol.Narrow defeats were experienced as more pleasant and increased motivation to play.

Socioeconomic status, perceived control, diurnal cortisol, and physical symptoms: A moderated mediation model

Social class is a robust predictor of health, with risk for disease and mortality increasing towards the lower end of the socioeconomic (SES) spectrum. While certain psychological characteristics, such as high sense of control, can protect low-SES individuals from adverse health outcomes, very few studies have investigated the biological mechanisms underlying these relationships. In this study, we tested whether sense of control mitigated the associations between SES and cortisol activity, and SES and physical health in daily life (i.e., number and severity of physical symptoms). Next, we tested whether individual differences in cortisol secretion would act as a mechanism by which SES and perceived control influenced physical health. In a large national sample from the Midlife in the United States (MIDUS) survey, we found that SES interacted with perceived control in predicting morning cortisol levels, cortisol slopes, number of physical symptoms, and severity of physical symptoms. Specifically, SES disparities in these health outcomes were more pronounced among individuals reporting low levels of perceived control than among individuals endorsing high levels of perceived control. Further, we found that a flatter cortisol slope mediated the link between lower SES and greater number and severity of physical symptoms for those individuals who reported lower levels of perceived control, but not for individuals reporting higher levels of perceived control. These findings suggest that perception of greater control may act as a buffer against the effect of low SES on health-related physiological processes.

Childhood Adversity, Self-Esteem, and Diurnal Cortisol Profiles Across the Life Span.

Childhood adversity is associated with poor health outcomes in adulthood; the hypothalamic-pituitary-adrenal (HPA) axis has been proposed as a crucial biological intermediary of these long-term effects. Here, we tested whether childhood adversity was associated with diurnal cortisol parameters and whether this link was partially explained by self-esteem. In both adults and youths, childhood adversity was associated with lower levels of cortisol at awakening, and this association was partially driven by low self-esteem. Further, we found a significant indirect pathway through which greater adversity during childhood was linked to a flatter cortisol slope via self-esteem. Finally, youths who had a caregiver with high self-esteem experienced a steeper decline in cortisol throughout the day compared with youths whose caregiver reported low self-esteem. We conclude that self-esteem is a plausible psychological mechanism through which childhood adversity may get embedded in the activity of the HPA axis across the life span.

Mothers’ Attachment is Linked to Their Children’s Anti-Inflammatory Gene Expression via Maternal Warmth

Research has demonstrated links between adult romantic attachment and one’s own physical health; little is known about links between adult attachment orientations and offspring health. Prior work has shown that parents’ greater attachment anxiety and avoidance predict less warmth toward their children. Extensive work has also shown that lower maternal warmth has negative downstream effects on offspring health. We tested the novel hypothesis that mothers’ dispositional romantic attachment would be linked—via maternal warmth—to their children’s expression of the glucocorticoid receptor gene NR3C1, higher expression of which is associated with healthier stress regulation and inflammatory response. In a sample of 132 youth with asthma, we found that mothers’ attachment anxiety and avoidance were both negatively associated with children’s expression of NR3C1, explained by lower youth-rated maternal warmth. Associations held after adjusting for demographic and psychosocial covariates. Implications for parents’ attachment influencing the health of offspring are discussed.

Biopsychosocial pathways linking subjective socioeconomic disadvantage to glycemic control in youths with type I diabetes

Older adolescent and young adults (OAYA) with type 1 diabetes (T1D) living in contexts of socio-economic disadvantage (SED) suffer disproportionately from poor glycemic control and related health complications. Although SED may convey a variety of risks, it may exacerbate diabetes-related stress levels, which in turn may account for observed disparities in health outcomes. The primary goal of the present study was to investigate the relationship between subjective SED, diabetes-related perceived stress, and diurnal cortisol secretion in urban OAYA with T1D. A secondary goal was to determine if cortisol was related to measures of blood glucose (HbA1c and mean blood glucose). Analyses were conducted among OAYA ages 17-20 years (n=61) affected by T1D, who provided daily saliva samples for four days, measures of glycemic control (i.e., HbA1c and mean blood glucose assessed via Continuous Glucose Monitor), and completed psychosocial questionnaires. We found that subjective SED was associated with a flatter diurnal cortisol rhythm via diabetes-related stress. Flattened cortisol rhythm was, in turn, associated with higher levels of HbA1c, but not with mean blood glucose assessed via Continuous Glucose Monitor. These results represent some of the first empirical evidence on how distal social factors (i.e., subjective SED) and proximal psychological processes (diabetes-related perceived stress) are connected to condition-relevant biological mechanisms (i.e., elevated HbA1c), via broad biological pathways implicated in health (i.e., flatter cortisol slope).