Most ungulates are gregarious species and outside the mating season are typically observed in single-sex groups. However little is known about the mechanisms underlying social segregation between sexes. We investigated the effect of conspecific attraction on individual spacing between unrestrained merino sheep Ovis aries and confined conspecifics. We considered differences between males and fem...

OBJECTIVES Social capital has been linked to self rated health and mortality rates. The authors examined the relations between measures of social capital and male/female mortality rates across counties in Hungary. DESIGN Cross sectional, ecological study. SETTING 20 counties of Hungary. PARTICIPANTS AND METHODS 12,640 people were interviewed in 1995 (the "Hungarostudy II" survey), represe...

Recent studies show that human and other mammalian breast milk may be tailored for the sex of the offspring. Such sex bias suggests that opposite-sex twins, who receive breast milk that cannot simultaneously be tailored for both sexes, may be at a disadvantage for growth compared with same-sex twins. An analysis of data from the National Longitudinal Study of Adolescent Health (Add Health) show...

It is expected that in humans, the lowered fitness of inbred offspring has produced a sexual aversion between close relatives. Generally, the strength of this aversion depends on the degree of relatedness between two individuals, with closer relatives inciting greater aversion than more distant relatives. Individuals are also expected to oppose acts of inbreeding that do not include the self, a...

INTRODUCTION Transsexual phenomenon is very complex, which is confirmed in everyday practice with these patients. There are many reasons why we have chosen to present this patient's case report. CASE OUTLINE The aim of this case report was to indicate how our female-to-male (FtM) transsexual patient tried to change her own sexual drive with the purpose of showing high adaptation in social env...

Gender stereotypes about math and science do not need to be endorsed, or even available to conscious introspection, to contribute to the sex gap in engagement and achievement in science, technology, engineering and mathematics (STEM). We examined implicit math attitudes and stereotypes among a heterogeneous sample of 5,139 participants. Women showed stronger implicit negativity toward math than...

Sex-limited expression of genetic or environmental factors occurs in two basic forms. First, the effects of a factor may be larger on one sex than on another, which is known as scalar sex limitation. Second, some factors may have an effect on one sex but not on the other, which is called nonscalar sex limitation. In the classical twin study, scalar sex-limited effects cause same-sex male and sa...