Relationships between ovarian hormone concentrations and mental rotations performance in naturally-cycling women

Circulating gonadal hormones have been linked to variation in the structure and function of the adult human brain, raising the question of how cognition is affected by sex hormones in adulthood. The impacts of progestogens and estrogens are of special interest due to the widespread use of hormone supplementation. Multiple studies have analyzed relationships between ovarian hormones and mental rotation performance, one of the largest known cognitive sex differences; however, results are conflicting. These discrepancies are likely due in part to modest sample sizes and reliance on self-report measures to assess menstrual cycle phase. The present study aimed to clarify the impact of progestogens and estrogens on visuospatial cognition by relating mental rotation task performance to salivary hormone concentrations. Across two studies totaling 528 naturally-cycling premenopausal women, an internal meta-analysis suggested a small, positive effect of within-subjects changes in progesterone on MRT performance (estimate = 0.44, p = 0.014), though this result should be interpreted with caution given multiple statistical analyses. Between-subjects differences and within-subject changes in estradiol did not significantly predict MRT. These results shed light on the potential cognitive effects of endogenous and exogenous hormone action, and the proximate mechanisms modulating spatial cognition.

Testosterone, cortisol, and secretory immunoglobulin-A within a single day and across two sequential days among trans- and cis-gender men

BACKGROUND

Previous research on the association between testosterone (T) and immunity has produced conflicting results.

OBJECTIVES

We address two potential reasons for these empirical inconsistencies in the present research. First, the association between T and immunity may depend on which branch of the immune system is considered. Here, we examine secretory IgA (sIgA), a measure of mucosal immunity functionally related to respiratory infection risk. Second, the association between T and immunity may depend on a third regulatory variable. Therefore, we examine the interaction between T and cortisol (CORT) as well as their independent and combined effects on mucosal immunity. To do this, we explore intra-individual associations between sIgA, CORT, and T within a single day (i.e., morning vs. evening) and across 2 sequential mornings. We target two samples of men: (1) cisgender (i.e., born and identifying as men), and (2) transgender (i.e., born female but identifying as men) undergoing T therapy for gender realignment.

MATERIALS AND METHODS

One hundred and forty-eight adult men (transgender n = 29) provided saliva samples at three time points: (1) upon waking, (2) before sleep on the same day, and (3) upon waking the following day. Samples were assayed in duplicate for sIgA, T and CORT.

RESULTS

For cisgender men, sIgA, T, and CORT exhibited clear circadian rhythms and were significantly related within and between samples. For transgender men, evidence for circadian change was found for sIgA and CORT, but not T. Further, sIgA was associated with CORT, but not T.

DISCUSSION AND CONCLUSIONS

This study provides the first evidence that salivary T and sIgA concentrations are associated within a single day and across sequential days for cisgender men. Differences between cis- and transgender men suggest that this may only be true for T levels driven by endogenous production; however, future studies should employ a larger sample size.

Does testosterone impair men's cognitive empathy? Evidence from two large-scale randomized controlled trials

The capacity to infer others' mental states (known as 'mind reading' and 'cognitive empathy') is essential for social interactions across species, and its impairment characterizes psychopathological conditions such as autism spectrum disorder and schizophrenia. Previous studies reported that testosterone administration impaired cognitive empathy in healthy humans, and that a putative biomarker of prenatal testosterone exposure (finger digit ratios) moderated the effect. However, empirical support for the relationship has relied on small sample studies with mixed evidence. We investigate the reliability and generalizability of the relationship in two large-scale double-blind placebo-controlled experiments in young men (n = 243 and n = 400), using two different testosterone administration protocols. We find no evidence that cognitive empathy is impaired by testosterone administration or associated with digit ratios. With an unprecedented combined sample size, these results counter current theories and previous high-profile reports, and demonstrate that previous investigations of this topic have been statistically underpowered.

Testosterone reduces the threat premium in competitive resource division

Like other animals, humans are sensitive to facial cues of threat. Recent evidence suggests that we use this information to dynamically calibrate competitive decision-making over resources, ceding more to high-threat individuals (who appear more willing/able to retaliate) and keeping more from low-threat individuals. Little is known, however, about the biological factors that support such threat assessment and decision-making systems. In a pre-registered, double-blind, placebo-controlled, cross-over testosterone administration study ( n = 118 men), we show for the first time that testosterone reduces the effects of threat on decision-making: participants ceded more resources to high-threat (versus low-threat) individuals (replicating the 'threat premium'), but this effect was blunted by testosterone, which selectively reduced the amount of resources ceded to those highest in threat. Thus, our findings suggest that testosterone influences competitive decision-making by recalibrating the integration of threat into the decision-making process.

Aggression Toward Sexualized Women Is Mediated by Decreased Perceptions of Humanness

Researchers have argued that the regulation of female sexuality is a major catalyst for women's intrasexual aggression. The present research examined whether women behave more aggressively toward a sexualized woman and whether this is explained by lower ratings of the target's humanness. Results showed that women rated another woman lower on uniquely human personality traits when she was dressed in a sexualized (vs. conventional) manner. Lower humanness ratings subsequently predicted increased aggression toward her in a behavioral measure of aggression. This effect was moderated by trait intrasexual competitiveness; lower humanness ratings translated into more aggression, but only for women scoring relatively high on intrasexual competition. Follow-up studies revealed that the effect of sexualized appearance on perceived humanness was not due to the atypicality of the clothing in a university setting. The current project reveals a novel psychological mechanism through which interacting with a sexualized woman promotes aggressive behavior toward her.

Using a Psychopharmacogenetic Approach To Identify the Pathways Through Which—and the People for Whom—Testosterone Promotes Aggression

Little is known about the neurobiological pathways through which testosterone promotes aggression or about the people in whom this effect is observed. Using a psychopharmacogenetic approach, we found that testosterone increases aggression in men ( N = 308) with select personality profiles and that these effects are further enhanced among those with fewer cytosine-adenine-guanine (CAG) repeats in exon 1 of the androgen receptor (AR) gene, a polymorphism associated with increased AR efficiency. Testosterone’s effects were rapid (~30 min after administration) and mediated, in part, by subjective reward associated with aggression. Testosterone thus appears to promote human aggression through an AR-related mechanism and to have stronger effects in men with the select personality profiles because it more strongly upregulates the subjective pleasure they derive from aggression. Given other evidence that testosterone regulates reward through dopaminergic pathways, and that the sensitivity of such pathways is enhanced among individuals with the personality profiles we identified, our findings may also implicate dopaminergic processes in testosterone’s heterogeneous effects on aggression.

Effect of exogenous testosterone on cooperation depends on personality and time pressure

The social heuristic hypothesis posits that human cooperation is an intuitive response that is expressed especially under conditions of time-constraint. Conversely, it proposes that for individuals given an opportunity for reflection, cooperation is more likely to be curtailed by an optimizing process calibrated to maximize individual benefit in a given situation. Notably, the steroid hormone testosterone has also been implicated in intuitive decision-making, including both prosocial and anti-social behaviors, with effects strongest in men with particular dispositional characteristics. This raises the possibility that increased testosterone may augment the effects predicted by the social heuristic hypothesis, particularly among men higher in specific dispositional characteristics (dominance, impulsivity, independent self-construal: high risk for testosterone-induced antisocial behavior). Here, in a testosterone administration study with a relatively large sample of men (N = 400), we test this possibility in a double-blind, placebo-controlled paradigm, with men randomly assigned to play a one-shot public goods game either under time-pressure (forced intuition) or with a time delay (forced reflection). Results revealed that within the placebo group, time-pressure (versus forced delay) increased cooperation among low risk men, but decreased cooperation among high risk men. Testosterone further moderated this pattern by abolishing the time-pressure effect in low risk men and-in high risk men-reversing the effect by selectively reducing offers (compared to placebo) under forced delay. This is the first evidence that testosterone and personality can interact with time-pressure and delay to predict human cooperation.

Exogenous Testosterone Rapidly Increases Aggressive Behavior in Dominant and Impulsive Men

BACKGROUND

Although traditional wisdom suggests that baseline levels of testosterone (T) promote aggressive behavior, decades of research have produced findings that have been largely weak and inconsistent. However, more recent experimental work suggests that exogenous administration of T rapidly potentiates amygdala and hypothalamus responses to angry facial expressions. Notably, these brain regions are rich in androgen receptors and play a key role in modulating aggressive behavior in animal models.

METHODS

The present experiment extends this work by examining whether acutely increasing T potentiates aggressive behavior in men. In a double-blind, placebo-controlled, between-subject design, healthy adult men (n = 121) were administered either T or placebo, and subsequently engaged in a well-validated decision-making game that measures aggressive behavior in response to social provocation. In light of prior correlational research, we also assessed the extent to which T's effects on aggressive behavior would depend on variability in trait dominance and/or trait self-control.

RESULTS

Exogenous T on its own did not modulate aggressive behavior. However, T's effects on aggression were strongly influenced by variation in trait dominance and trait self-control. Specifically, T caused an increase in aggressive behavior, but only among men scoring relatively high in trait dominance or low in trait self-control.

CONCLUSIONS

These findings are the first to demonstrate that T can rapidly (within 60 minutes) potentiate aggressive behavior, but only among men with dominant or impulsive personality styles.

Effects of exogenous testosterone and mating context on men's preferences for female facial femininity

Correlational research suggests that men show greater attraction to feminine female faces when their testosterone (T) levels are high. Men's preferences for feminine faces also seem to vary as a function of relationship context (short versus long-term). However, the relationship between T and preferences for female facial femininity has yet to be tested experimentally. In the current paper, we report the results of two experiments examining the causal role of T in modulating preferences for facial femininity across both short and long-term mating contexts. Results of Experiment 1 (within-subject design, n=24) showed that participants significantly preferred feminized versus masculinized versions of women's faces. Further, participants showed a stronger preference for feminine faces in the short versus the long-term context after they received T, but not after they received placebo. Post-hoc analyses suggested that this effect was driven by a lower preference for feminine faces in the long-term context when on T relative to placebo, and this effect was found exclusively for men who received placebo on the first day of testing, and T on the second day of testing (i.e., Order x Drug x Mating context interaction). In Experiment 2 (between-subject design, n=93), men demonstrated a significant preference for feminized female faces in the short versus the long-term context after T, but not after placebo administration. Collectively, these findings provide the first causal evidence that T modulates men's preferences for facial femininity as a function of mating context.