Sex differences in same-sex direct aggression and sociosexuality are among the most robust in the literature. The present article evaluated the hypothesis that both can be explained by a sex difference in the willingness to take impulsive risks. Self-report data were gathered from 3,775 respondents (1,514 female) on same-sex aggression, sociosexuality, and risky impulsivity. Risky impulsivity w...

This study was designed to determine the ability of computer-assisted sperm morphometry analysis (CASA-Morph) with fluorescence to discriminate between spermatozoa carrying different sex chromosomes from the nuclear morphometrics generated and different statistical procedures in the bovine species. The study was divided into two experiments. The first was to study the morphometric differences b...

Human mating and reproductive behaviour can vary depending on various mechanisms, including the local sex ratio. Previous research shows that as sex ratios become female-biased, women from economically deprived areas are less likely to delay reproductive opportunities to wait for a high-investing mate but instead begin their reproductive careers sooner. Here, we show that the local sex ratio al...

Nettie M. Stevens is one of the first women who contributed to genetic research. She discovered the role of sex chromosomes in sex determination during the first decade of the twentieth century. However, her discovery has rarely been recognized, and her scientific reputation was eclipsed by that of T.H. Morgan, who was credited for the establishment of modern genetics. Her name is absent from m...

The objective of the current study was to further examine gender differences in preferences for particular characteristics in a sexual partner and to investigate the extent to which men and women accurately estimate the preferences of the other gender. Heterosexual college students (185 men, 244 women) rated a diverse set of characteristics in a hypothetical sexual partner with whom they were p...

Puberty heralds the onset of adulthood, and is fraught with complex physiological and psychological changes and emotions. In this study, we looked at the sources of information about puberty and sex education among males and females, age at which they learned about them, and the opinions on the role of schools and parents in imparting this education among medical students.A cross-sectional pilo...

Although it is commonly believed that women are kinder and more cooperative than men, there is conflicting evidence for this assertion. Current theories of sex differences in social behavior suggest that it may be useful to examine in what situations men and women are likely to differ in cooperation. Here, we derive predictions from both sociocultural and evolutionary perspectives on context-sp...

We examined sex differences in kidney mineral concentrations and urinary albumin excretion in rats given feed containing various phosphorus (P) levels. With feed that was 0.6%, 0.9%, 1.2%, and 1.5% P, kidney calcium and P concentrations were higher in female rats than in male rats. With 1.2% or 1.5% P, urinary albumin excretion was higher in the female rats. The sex of the animal affected the k...

Recent studies in a representative selection of holometabolous insects suggest that, despite diversity at the instructive level, the signal-relaying part of the sex-determining pathway is remarkably well conserved. In principle, it is composed of the transformer gene (tra), which acts as a common binary switch that transduces the selected sexual fate, female when ON, male when OFF, to the downs...

OBJECTIVES To estimate the proportion of individuals in the general population who did not notify their sexual partners at the time of an STD diagnosis, according to the sex of the patient and the type of partner. METHODS We analysed behaviour at the time of diagnosis of a self reported STD, using data from three large French national population based surveys of adults (ACSF, Barométre Santé)...