Male mice actively direct their urine at nearby females, and this urine reliably contains unconjugated oestradiol (E 2 ) and other steroids. Giving inseminated females minute doses of exogenous E 2 , either systemically or intranasally, can cause failure of blastocyst implantation. Giving juvenile females minute doses of exogenous E 2 promotes measures of reproductive maturity such as uterine mass. Here we show that tritium-labelled E 2 ( 3 H-E 2 ) can be traced from injection into novel male mice to tissues of cohabiting inseminated and juvenile females. We show the presence of 3 H-E 2 in male excretions, transmission to the circulation of females and arrival in the female reproductive tract. In males, 3 H-E 2 given systemically was readily found in reproductive tissues and was especially abundant in bladder urine. In females, 3 H-E 2 was found to enter the system via both nasal and percutaneous routes, and was measurable in the uterus and other tissues. As supraoptimal E 2 levels can both interfere with blastocyst implantation in inseminated females and promote uterine growth in juvenile females, we suggest that absorption of male-excreted E 2 can account for major aspects of the Bruce and Vandenbergh effects.

No abstract

In most countries around the world, the population is rapidly aging. A by-product of these demographic shifts is that older adults will likely occupy more positions of power and influence in our societies than ever before. Further, cultural differences might shape how these transitions unfold around the globe. Across two studies, we investigated whether business and political leaders differed in age across various cultures. Study 1 (N = 1,034) showed that business leaders were significantly older in Eastern (e.g., China, India, and Japan) cultures than Western (e.g., United States, Sweden, and United Kingdom) cultures, even while controlling for population structure (e.g., percentage of elderly in the society), gross domestic product (GDP), and wealth distribution across the population (GINI). Study 2 (N = 1,268) conceptually replicated these findings by showing that political leaders were once again older in Eastern vs. Western cultures. Furthermore, cultural tightness mediated the relationship between culture and older leadership. These findings highlight how cultural differences impact not only our preferences, but also important outcomes in consequential domains such as business and politics. Potential explanations for why cultural tightness may be related to differences in leader age across cultures are discussed. To build on these findings, future research should assess the potential causal mechanisms underlying the cultural effect on leader age, and explore the various practical implications of this effect.

Emerging research is beginning to highlight the influence of mindfulness on cognitive performance. However, researchers have yet to examine how mindfulness impacts cognition after people experience adversity or challenge within a task. The present study aims to build upon the existing theoretical knowledge base by investigating how a low‐dose mindfulness induction influences engagement, mood, performance, and persistence on a challenging cognitive task. It was hypothesized that compared to a wait‐list control group, mindful individuals would experience greater engagement, more adaptive mood, and enhanced performance on the difficult cognitive task. Results indicated that although the mindfulness and wait‐list control groups did not differ in how strenuous (difficult, stressful) they found the task, the mindfulness group reported significantly greater levels of engagement. Moreover, the mindfulness group reported higher levels of low‐arousal positive mood (e.g., calmness, tranquility) compared to the control group following the task. After exposure to the adversity component of the task, mindful individuals also responded with increased performance and persistence compared to the control group on a follow‐up task. Practical applications of these findings are discussed.

No abstract