Gender differences in egalitarian behavior and attitudes in early childhood.

It is axiomatic that human females are more egalitarian than males. However, surprisingly little empirical research exists that empirically assesses this stereotype. We created two studies designed to objectively examine egalitarian behavior in 3- to 5-year-old children. In Study 1 we compared the egalitarian behavior and attitudes of American girls versus boys by tabulating the extent to which each gender awarded the same number of stickers to, and liked to the same degree, two puppets. One puppet followed the child's instructions or actions while the other did not during a drawing task in which the child played the roles of leader and peer. In the peer role, girls exhibited more egalitarian behavior than boys. In Study 2, French-Canadian children were shown two drawings by unknown peers-one messily and one neatly colored-, then asked to distribute stickers to each peer's drawing. Again, girls exhibited more egalitarian behavior than boys. Results suggest the origins of gender differences in egalitarian behavior occur early in life and merit further investigation.

Understanding boys' underrepresentation in private and enriched programmes during the transition to secondary school.

BACKGROUND: In the past decades, there has been a growing concern to understand why boys struggle in school. One of the turning points in students' educational trajectories likely to exacerbate boys' academic difficulties is students' enrolment in private or enriched school programmes, as boys are underrepresented in such programmes. METHOD: To better understand this gender imbalance, our research draws on a longitudinal design to examine whether grade 6 students' externalizing behaviours, school engagement and school grades in mathematics and language arts relate to secondary school programme attendance, among a sample size of 577 students (277 boys). RESULTS: Path analysis showed that only language arts grades predicted enrolment in private or selective public programmes and contributed to boys' underrepresentation in these programmes. CONCLUSIONS: Such findings have important implications for understanding boys' underachievement and low persistence in school as well as to guide interventions to promote gender and overall educational equity in school.

Girls exhibit greater empathy than boys following a minor accident.

Hundreds of studies find that girls and women report feeling greater empathy than boys and men in response to adverse events befalling others. Despite this, few non-self-report measures demonstrate similar sex differences. This produces the oft-cited conclusion that to conform to societal expectations of appropriate sex-typed behavior females report higher levels of empathy. Several studies of sex differences in areas of brain activation and on infants' and young children's behavior however provide suggestive findings that self-reports reflect actual underlying sex differences in experiencing concern about others. We demonstrate using behavioral indices that females experience more empathy than males after witnessing an adverse event befall a same-sex classmate. In our study, one member of a pair experienced a minor accident on the way to constructing a tower while a bystander observed. We measured whether bystanders ceased their ongoing activity, looked at the victim, waited for the victim to recover from the accident, and actively intervened to help the victim. Female more than male bystanders engaged in these activities. These behavioral results suggest that an adverse event produces different subjective experiences in females than males that motivate objectively different behaviors, consistent with findings from self-report measures of empathy.

High status males invest more than high status females in lower status same-sex collaborators.

Studies on human cooperation using economic games rarely include ecologically relevant factors. In studies on non-human primates however, both status and sex typically influence patterns of cooperation. Across primate species, high status individuals are more likely to cooperate, though this depends on the species-specific social structure of each sex. Based on human social structure, we predict that higher status males who interact more in hierarchical groups than females, will invest more than high status females in valued same-sex peers after successful cooperation. Across three studies, 187 male and 188 female participants cooperated with a (fictitious) same-sex partner who varied in competence. Participants then divided a reward between themselves and their partner. High status was induced in three different ways in each study, social influence, leadership and power. No overall sex difference in reward sharing was observed. Consistent with the hypothesis however, across all three studies, high status males invested more than high status females in cooperative partners, suggesting that high status males intuitively evaluate sharing rewards with same-sex partners as more beneficial.

Chronic treatments with a 5-HT4 receptor agonist decrease amyloid pathology in the entorhinal cortex and learning and memory deficits in the 5xFAD mouse model of Alzheimer's disease.

Alzheimer's disease (AD) is the main cause of dementia and a major health issue worldwide. The complexity of the pathology continues to challenge its comprehension and the implementation of effective treatments. In the last decade, a number of possible targets of intervention have been pointed out, among which the stimulation of 5-HT4 receptors (5-HT4Rs) seems very promising. 5-HT4R agonists exert pro-cognitive effects, inhibit amyloid-ß peptide (Aß) production and therefore directly and positively impact AD progression. In the present work, we investigated the effects of RS 67333, a partial 5-HT4R agonist, after chronic administration in the 5xFAD mouse model of AD. 5xFAD male mice and their wild type (WT) male littermates received either RS 67333 or vehicle solution i.p., twice a week, for 2 or 4 months. Cognitive performance was evaluated in a hippocampal-dependent behavioral task, the olfactory tubing maze (OTM). Mice were then sacrificed to evaluate the metabolism of the amyloid precursor protein (APP), amyloidosis and neuroinflammatory processes. No beneficial effects of RS 67333 were observed in 5xFAD mice after 2 months of treatment, while 5xFAD mice treated for 4 months showed better cognitive abilities compared to vehicle-treated 5xFAD mice. The beneficial effects of RS 67333 on learning and memory correlated with the decrease in both amyloid plaque load and neuroinflammation, more specifically in the entorhinal cortex. The most significant improvements in learning and memory and reduction of pathology stigmata were observed after the 4-month administration of RS 67333, demonstrating that treatment duration is important to alleviate amyloidosis and glial reactivity, particularly in the entorhinal cortex. These results confirm the 5-HT4R as a promising target for AD pathogenesis and highlight the need for further investigations to characterize fully the underlying mechanisms of action.

Early administration of RS 67333, a specific 5-HT4 receptor agonist, prevents amyloidogenesis and behavioral deficits in the 5XFAD mouse model of Alzheimer's disease.

Amyloid ß (Aß) accumulation is considered the main culprit in the pathogenesis of Alzheimer's disease (AD). Recent studies suggest that decreasing Aß production at very early stages of AD could be a promising strategy to slow down disease progression. Serotonin 5-HT4 receptor activation stimulates α-cleavage of the amyloid precursor protein (APP), leading to the release of the soluble and neurotrophic sAPPα fragment and thus precluding Aß formation. Using the 5XFAD mouse model of AD that shows accelerated Aß deposition, we investigated the effect of chronic treatments (treatment onset at different ages and different durations) with the 5-HT4 receptor agonist RS 67333 during the asymptomatic phase of the disease. Chronic administration of RS 67333 decreased concomitantly the number of amyloid plaques and the level of Aß species. Reduction of Aß levels was accompanied by a striking decrease in hippocampal astrogliosis and microgliosis. RS 67333 also transiently increased sAPPα concentration in the cerebrospinal fluid and brain. Moreover, a specific 5-HT4 receptor antagonist (RS 39604) prevented the RS 67333-mediated reduction of the amyloid pathology. Finally, the novel object recognition test deficits of 5XFAD mice were reversed by chronic treatment with RS 67333. Collectively, these results strongly highlight this 5-HT4 receptor agonist as a promising disease modifying-agent for AD.