According to the dual-hormone hypothesis, the relationship between testosterone and status-relevant behavior is moderated by cortisol, suggesting this relationship only exists when cortisol is low. In the current study, a meta-analysis (including 30 papers with 33 studies, 49 effect sizes, n = 8538) on the interaction effect of testosterone and cortisol on status-relevant behavior (i.e. status, dominance, risk taking, aggression, and psychopathy) was performed. There was only marginal support for the dual-hormone hypothesis: The effect size of the interaction between testosterone and cortisol on status-relevant behavior was significant but very small (r = -.061, p =  .026), which was corroborated by follow-up meta-analyses on simple slopes on low and high cortisol. Effect sizes were largest for direct status measures, although not significantly different from other outcome measures. Similarly, effect sizes seemed larger for men than for women. However, robustness analyses indicated signs of publication bias, enhanced significance due to potential flexibility in data-analysis, and a lack of power of individual studies, emphasizing the need for a large, pre-registered study.

Previous research suggests that sexual stimuli increase testosterone (T) in women and shows inconsistent effects of sexual arousal on cortisol (C), but effects of cognitive aspects of arousal, rather than behaviors or sensory stimuli, are unclear. The present study examined whether sexual thoughts affect T or C and whether hormonal contraceptive (HC) use moderated this effect, given mixed findings of HC use confounding hormone responses. Participants (79 women) provided a baseline saliva sample for radioimmunoassay. We created the Imagined Social Situation Exercise (ISSE) to test effects of imagining social interactions on hormones, and participants were assigned to the experimental (sexual) or one of three control (positive, neutral, stressful) conditions. Participants provided a second saliva sample 15 min post-activity. Results indicated that for women not using HCs, the sexual condition increased T compared to the stressful or positive conditions. In contrast, HC using women in the sexual condition had decreased T relative to the stressful condition and similar T to the positive condition. The effect was specific to T, as sexual thoughts did not change C. For participants in the sexual condition, higher baseline T predicted larger increases in sexual arousal but smaller increases in T, likely due to ceiling effects on T. Our results suggest that sexual thoughts change T but not C, baseline T levels and HC use may contribute to variation in the T response to sexual thoughts, and cognitive aspects of sexual arousal affect physiology.

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.

Anabolic-androgenic steroid (AAS) abuse is implicated in maladaptive decision making such as increased risk taking and problem gambling. Endogenous testosterone correlates with economic risk taking in both the stock market (Coates & Herbert, 2008) and in the laboratory, as measured by the Iowa Gambling Task (Stanton, Liening, & Schultheiss, 2011). Additionally, AAS use has been associated with problem gambling behavior in adolescents (Proimos, DuRant, Pierce, & Goodman, 1998). Thus, AAS may impair economic decision making. However, studies of human AAS users cannot control for preexisting risky behavior or normalize androgen levels. Accordingly, the present study investigated AAS effects on decision making in rats using a novel, balanced rodent model of the IGT. Adolescent male Long-Evans rats were treated chronically with high-dose testosterone (7.5 mg/kg) or vehicle (13% cyclodextrin in water) sc, and trained to work for sugar pellets in an operant chamber equipped with 4 levers, each associated with a different schedule of reward magnitude (number of pellets), probability, and punishment (time-out) duration. By RM-ANOVA, there was a main effect of lever (F3,78 = 25.33, p < .05), such that all rats preferred lever L4 offering a large reward (4 pellets), but with low probability (45%) and a long (35 sec) time-out. There was also a significant interaction of testosterone × lever (F3,78 = 2.78, p < .05), with testosterone increasing preference for L4 and decreasing preference for the other levers, relative to vehicle-treated controls. These data extend our previous findings of altered decision making in AAS-treated rats, and suggest that AAS may alter economic decision making in human users.

Testosterone plays a key role in shaping human social behavior. Recent findings have linked testosterone to altruistic behavior in economic decision tasks depending on group membership and intergroup competition. The preferential treatment of ingroup members, while aggression and discrimination is directed towards outgroup members, has been referred to as parochial altruism. Here we investigated in two consecutive studies, whether testosterone is associated with parochial altruism depending on individual tendency for costly punishment. In the first study, 61 men performed a single-shot ultimatum game (UG) in a minimal group context, in which they interacted with members of an ingroup and outgroup. In the second study, 34 men performed a single-shot UG in a more realistic group context, in which they responded to the proposals of supporters of six political parties during the German election year 2017. Political parties varied in their social distance to the participants’ favorite party as indicated by an individual ranking. Participants of study 2 also performed a cued recall task, in which they had to decide whether they had already encountered a face during the previous UG (old-new decision). In order to make the UG data of study 2 most comparable to the data of study 1, the rejection rates of several parties were combined according to the social distance ranking they achieved. Parties ranked 1 to 3 formed the relatively close and favored ‘ingroup’ that shared similar political values with the participant (e.g., left wing parties), while the ‘outgroup’ consisted of parties ranked from 4 to 6 with more distant or even antagonistic political views (e.g., conservative to right wing parties). In both studies, results showed a parochial pattern with higher rejection rates made in response to outgroup compared to ingroup offers. Interestingly, across studies higher salivary testosterone was associated with higher rejection rates related to unfair outgroup offers in comparison to the unfair offers made by ingroup members. The present findings suggest that latent intergroup biases during decision-making may be positively related to endogenous testosterone. Similar to previous evidence that already indicated a role of testosterone in shaping male parochial altruism in male soccer fans, these data underscore the general, yet rather subtle role of male testosterone also in other social settings.

Purpose Although acute exercise has been demonstrated to modulate endogenous testosterone levels, existing studies have reached conflicting conclusions regarding the pattern of response of testosterone levels after exercise. The objective of this study was to examine the dynamic effects of acute exercise on testosterone levels and to analyze the differences in the role of factors such as exercise mode, intensity, sample source, and gender. Methods A comprehensive search of articles published up to March 2025 was conducted in five database systems, including PubMed and Web of Science, in accordance with the PRISMA guidelines. A total of 15 randomized controlled trials assessing the effect of acute exercise on testosterone levels were included, with a total sample size of 251 participants. Results (1) Testosterone levels demonstrate a greater increase following resistance training, with a delayed return to baseline levels; in contrast, testosterone levels typically recover within 1 h after aerobic exercise. (2) Moderate to high-intensity exercise stimulates the hypothalamic-pituitary-gonadal axis (HPG), leading to a transient rise in testosterone, but extended high-intensity exercise causes testosterone suppression during recovery due to cortisol antagonism for up to 72 h. The testosterone concentration during the active phase exceeds that during the recovery period. (3) A significant disparity in baseline testosterone levels exists between males and females, with males exhibiting higher levels. Additionally, males demonstrate a more pronounced response to exercise compared to females. (4) Blood tests exhibit greater sensitivity than saliva tests, although the latter is more reactive to high-intensity exercise; (5) The response is more pronounced in younger males compared to older adults, with negligible response observed in adolescents. Conclusion Variations in testosterone level modulation due to acute exercise are predominantly influenced by exercise mode, intensity, sample source, and subject characteristics (gender and age). While resistance training and high-intensity exercise might temporarily increase testosterone levels, it is essential to consider the potential for hormonal imbalance after recovery; age and sex variations, along with assay standardization, are critical areas for further investigation. This review was registered PROSPERO with registration number CRD420251007222.

circadian rhythms, and is important in certain social behaviors, such as sexual and aggressive behaviors. The hypothalamus is divided into four regions (preoptic The hypothalamus (pl.: hypothalami; from Ancient Greek ὑπό (hupó) 'under' and θάλαμος (thálamos) 'chamber') is a small part of the vertebrate brain that contains a number of nuclei with a variety of functions. One of the most important functions is to link the nervous system to the endocrine system via the pituitary gland. The hypothalamus is located below the thalamus and is part of the limbic If a female rat is given testosterone in the first few days of postnatal life, during the "critical period" of sex-steroid influence in rats, the hypothalamus is irreversibly defeminized and masculinized; the adult rat will be incapable of generating an LH surge in response to estrogen as is characteristic of females, but will be capable of exhibiting male sexual behaviors e.g. mounting a sexually receptive female. By contrast, a male rat castrated just after birth will be feminized, and the adult will show typical female "receptive" sexual behavior in response to estrogen, that is, lordosis behavior. Masculinization and feminization can be distinguished from their complimentary de-feminization and de-masculinization, as neonatal treatment with COX2 inhibitors or PgE2 makes it possible to create rats which exhibit neither sexual behaviour, or both, respectively. Some effects of combined masculinization and feminization on hypothalamic physiology are known, but outcomes where the processes oppose (e.g. proportions of cell types) remain unreported in vitro as of 2025. In primates, the developmental influence of androgens is less clear, and the consequences are less understood. Within the brain, testosterone is aromatized (to estradiol), which is the principal active hormone for developmental influences. The human testis secretes high levels of testosterone from about week eight of fetal life until five to six months after birth (a similar perinatal surge in testosterone is observed in many species), a process that appears to underlie the male phenotype. Estrogen from the maternal circulation is relatively ineffective, partly because of the high circulating levels of steroid-binding proteins in pregnancy. Sex steroids are not the only important influences upon hypothalamic development; in particular, pre-pubertal stress in early life (of rats) determines the capacity of the adult hypothalamus to respond to an acute stressor. Unlike gonadal steroid receptors, glucocorticoid receptors are very widespread throughout the brain; in the paraventricular nucleus, they mediate negative feedback control of CRF synthesis and secretion, but elsewhere their role is not well…

arousal, including testosterone, cortisol, and estradiol. However, the specific roles of these hormones are not clear. Testosterone is the most commonly Sexual arousal (also known as sexual excitement) describes the physiological and psychological responses in preparation for sexual intercourse or when exposed to sexual stimuli. A number of physiological responses occur in the body and mind as preparation for sexual intercourse, and continue during intercourse. Male arousal leads to erection, cremaster reflex and pre-ejaculate; in female arousal, Sev…

<b>Background/Objectives:</b> Intermittent fasting (IF) has gained increasing attention as a nutritional strategy to improve metabolic health, body composition, and disease-related outcomes. However, its effects are often interpreted as broadly uniform, despite growing evidence that biological sex may modulate fasting responses. This narrative review examines sex-specific differences in the physiological, endocrine, clinical, and psychosocial effects of IF in women and men. <b>Methods:</b> We conducted a narrative synthesis of human and preclinical evidence addressing IF protocols, mechanisms, benefits, adverse effects, and sex-related differences. Particular attention was given to substrate metabolism, hormonal regulation, neuroendocrine sensitivity, energy availability, exercise performance, chronic disease management, aging-related outcomes, and psychological or behavioral responses. <b>Results:</b> The available literature suggests that women and men share several beneficial responses to IF, including improvements in body composition and cardiometabolic markers, but may differ in the magnitude, tolerability, and mechanistic basis of these effects. Women appear to show greater sensitivity of reproductive and neuroendocrine function to energetic stress, particularly under conditions of low energy availability, high exercise load, or reproductive vulnerability. In contrast, men may exhibit preserved functional outcomes despite measurable endocrine adaptations, including changes in testosterone dynamics. Across both sexes, responses vary according to fasting protocol, nutritional adequacy, baseline metabolic status, life stage, and clinical context. <b>Conclusions:</b> Current evidence supports a sex-informed and context-specific interpretation of IF rather than universally applicable fasting prescriptions. Direct sex-comparative studies remain scarce, and many conclusions are inferred from parallel male and female studies. Future research should integrate sex as a core biological variable in precision nutrition and fasting-based interventions.