Sex differences in lateralisation have been examined frequently, but have found varying and contradictory results. The experiment presented in this paper examines the lateralisation of processing positive facial emotion in 276 right handed undergraduates (138 males, 138 females). All participants completed two behavioural tests of lateralisation: a handedness preference questionnaire and a chim...

This question could be asked about sex: the verb or sex: the noun. In noun form, sex (or sex assigned at birth) is a term used to describe physical or genetic markers ? more specifically, hormones, genes, and reproductive organs. Biologically speaking, it's a myth that there are only two sexes, male and female. All physical sex characteristics ? from genitals, to hormones, to chromosomes ? fall...

The effect of nest aggregation in courtship behaviour was tested experimentally in an ecologically constrained, sex-role reversed population of the peacock blenny Salaria pavo. Mixed sex groups of eight males and eight females were tested in experimental tanks, containing eight potential nests either aggregated or dispersed. In the aggregated treatment, males spent more time inside their nests ...

In his recent investigation “Atomic bomb testing and its effects on global male to female ratios at birth” [1], Victor Grech reports a rising birth sex ratio in most regions in temporal association with atomic weapon testing. Therefore, Grech’s observation corroborates corresponding findings across Europe after the nuclear Windscale fire [2, 3], after the Chernobyl accident [4–6], and in Cuba [...

An extrachromosomal factor, termed son-killer (sk), affects the sex ratio in a parasitoid wasp, Nasonia (=Mormoniella) vitripennis. The factor is maternally transmitted and alters the secondary sex ratio of an infected female through mortality of approximately 80% of the male embryos. No effect on the primary (zygotic) sex ratio is observed. Ninety-five percent of the daughters of an infected f...

OBJECTIVES This study examined the changes in running performance and the sex differences between women and men in 24-hour ultra-marathons held worldwide from 1977 to 2012. METHOD Changes in running speed and ages of the fastest 24-hour ultra-marathoners were determined using single- and multi-level regression analyses. RESULTS From 1977 to 2012, the sex differences in 24-hour ultra-maratho...

Social learning provides an effective route to gaining up-to-date information, particularly when information is costly to obtain asocially. Theoretical work predicts that the willingness to switch between using asocial and social sources of information will vary between individuals according to their risk tolerance. We tested the prediction that, where there are sex differences in risk toleranc...

Few sex differences in regret or counterfactual thinking are evident in past research. The authors discovered a sex difference in regret that is both domain-specific (i.e., unique to romantic relationships) and interpretable within a convergence of theories of evolution and regulatory focus. Three studies showed that within romantic relationships, men emphasize regrets of inaction over action (...

The friends with benefits relationship (FWBR) is a complex, opposite-sex friendship in which partners freely engage in sexual activity within the relationship, but do not interact as romantic partners, but rather as platonic friends. And while framed as apparently beneficial, the current study attempted to determine if, in fact, any relational benefits actually exist within the FWBR as compared...

This paper has the three objectives of attempting to replicate a previous study in which it was found that males have substantially greater general knowledge in most fields or domains than females, and of determining how far sex differences in general knowledge are a function of differences in either Gf (fluid intelligence), or experience. The results confirmed the previous study to the effect ...