Women infected with parasite Toxoplasma have more sons

The boy-to-girl ratio at birth (secondary sex ratio) is around 0.51 in most populations. The sex ratio varies between societies and may be influenced by many factors, such as stress and immunosuppression, age, primiparity, the sex of the preceding siblings and the socioeconomic status of the parents. As parasite infection affects many immunological and physiological parameters of the host, we analyzed the effect of latent toxoplasmosis on sex ratios in humans. Clinical records of 1,803 infants born from 1996 to 2004 contained information regarding the mother’s age, concentration of anti-Toxoplasma antibodies, previous deliveries and abortions and the sex of the newborn. The results of our retrospective cohort study suggest that the presence of one of the most common parasites (with a worldwide prevalence from 20 to 80%), Toxoplasma gondii, can influence the secondary sex ratio in humans. Depending on the antibody concentration, the probability of the birth of a boy can increase up to a value of 0.72, C.I.₉₅ = (0.636, 0.805), which means that for every 260 boys born, 100 girls are born to women with the highest concentration of anti-Toxoplasma antibodies. The toxoplasmosis associated with immunosuppression or immunomodulation might be responsible for the enhanced survival of male embryos. In light of the high prevalence of latent toxoplasmosis in most countries, the impact of toxoplasmosis on the human population might be considerable.     

Forest clearing and sex ratio in forest-dwelling wood ant <Emphasis Type="Italic">Formica aquilonia</Emphasis>

Sex ratios of ants have been shown to vary with food resource levels in several studies, but it is not known whether forest clear-cutting has any effect on sex ratio of aphid-tending forest-dwelling ants. We investigated whether the offspring sex ratio of the forest dwelling ant Formica aquilonia varied as a response to clear-cutting. We found that the proportion of males was smaller in clear-cuts than in adjacent forests. Our results are among the first showing that anthropogenic changes in forest structures may have a potential to modify sex ratios of social insects and other forest-dwelling animals.     

Spillover and crossover of sex‐based harassment from work to home: Supervisor gender harassment affects romantic relationship functioning via targets' anger

We investigate how gender harassment affects the romantic relationships (i.e., romantic relationship adjustment and romantic relationship efficacy) of female targets (spillover effects) and their romantic partners (crossover effects), and what role targets' anger in response to their gender harassment plays in these relationships. We explored these questions using two US samples. Sample 1 comprised 206 females, all of whom provided data on their gender harassment experiences, feelings of anger, and romantic relationship functioning. Sample 2 consisted of 60 romantic dyads. Females once again provided data on their gender harassment experiences and feelings of anger; their romantic partners reported on their own romantic relationship functioning. Full support emerged for hypothesized spillover effects: supervisor gender harassment indirectly and negatively influenced targets' romantic relationship adjustment and romantic relationship efficacy through target anger (Sample 1). Full support also emerged for hypothesized crossover effects: supervisor gender harassment indirectly and negatively influenced the romantic relationship adjustment and romantic relationship efficacy of targets' romantic partners through target anger (Sample 2). Implications for theory, research, and practice are considered. Copyright © 2014 John Wiley & Sons, Ltd.