Male-related chemical cues promote sexual receptivity in the female musk shrew

The role of conspecific chemical cues in the activation of sexual behavior was investigated in the female musk shrew (Suncus murinus). In Experiment 1, virgin female musk shrews were exposed to either clean cages or cages recently vacated by an adult male. Regardless of whether the male used for the sexual behavior test was "familiar" to the female (having spent the 24 h exposure in his vacant cage) or "unfamiliar," females exposed to male-related cues received mounts from males significantly sooner than females exposed to clean cages. In Experiment 2, females housed for 24 h in a cage soiled by an adult male allowed males to mount significantly sooner than females housed in a cage soiled by a castrated male, another female, or a clean cage. These results demonstrate that chemical cues, produced exclusively by adult males, promote sexual receptivity in female musk shrews.     

Parents’ Beliefs about High School Students’ Spatial Abilities: Gender Differences and Associations with Parent Encouragement to Pursue a STEM Career and Students’ STEM Career Intentions

In the present study, we investigated whether parents’ beliefs about their high school aged adolescents’ spatial abilities (i.e., spatial visualization, mental manipulation, and navigation abilities) differed based on their child’s gender. We also examined whether these beliefs related to parents’ encouragement of their child to pursue a Science, Technology, Engineering, or Mathematics (STEM) career as well as students’ actual STEM major and career intentions. Data were collected from 117 pairs of U.S. high school students and one of their parents. We found that parents of young men thought their child had higher mental manipulation and navigation abilities than did parents of young women, even after statistically controlling for adolescents’ actual spatial abilities. Parents who perceived that their child had higher mental manipulation ability were more likely to encourage their child to pursue a STEM career, and those students were more likely to report that they intended to pursue a STEM career. These findings suggest that parents’ beliefs about how good their child is at spatial tasks may be based more strongly on gender stereotypes than on their child’s actual spatial abilities. Helping to make parents aware of these beliefs could be a potential lever of intervention to increase women’s participation in STEM careers.

     

Maternal involvement and children’s academic motivation and achievement: The roles of maternal autonomy support and children’s affect

Motivation and Emotion - Parents’ level of involvement in children’s schooling is related to children’s academic success; yet, few studies have considered factors that may play a...     

Assessment of mothers' concerns about infants,toddlers, and preschoolers

Only recently has determining the child-rearing concerns of parents been considered an important research objective. Existing efforts have, for the most part, either employed small sample sizes or surveyed parents already in the process of seeking help or advice. It was, therefore, felt that additional, more representative data were needed. In the present study, 583 mothers with children aged 59 months or younger were surveyed regarding their concerns about their children's development. On the „Specific Needs Assessment Report”︁ (SNAR) (copyright © 1975, by Karl F. Riem, J. Jeffrey Crisco, and Kathy Willms), mothers rated their concerns for 60 developmental-behavioral items about their children's health, attending skills, problem behaviors, communication skills, motor skills, cognitive skills, self-help skills, and social skills. Mothers were most frequently concerned to a moderate or major degree about at least one item of the problem behavior category. For this category, parent-child management, crying-whining, and temper tantrums were the individual items of greatest concern. Mothers of girls more frequently indicated health concerns than mothers of boys. These results support those of previous investigations, which suggested the need for parent education programs to help parents manage their children.     

Elevation and reduction of plasma tryptophan and their effects on aggression and perceptual sensitivity in normal males

Data from experimental animals suggest that 5-hydroxytryptamine (5HT) may have an inhibitory effect on aggression, while clinical studies have found a correlation between pathological aggression and low brain 5HT. To investigate this relationship further we used amino acid mixtures designed to raise or lower the levels of the 5HT precursor, tryptophan. Normal male subjects were given tryptophan-depleted, balanced, or tryptophan-supplemented ammo acid mixtures and tested for aggression 5 hours later. The balanced amino acid mixture served as a control for the tryptophan depletion and supplementation. Testing for aggression was done using the Buss paradigm in which subjects deliver electric shocks to a (nonexistent) partner in response to stimulus tones. Duration and intensity of shock delivered were the measures of aggression, while responsivity to the stimulus tones was the measure of perceptual sensitivity. Neither tryptophan supplementation nor tryptophan depletion had any effect on these measures of aggression or perceptual sensitivity. We conclude that raising or lowering the synthesis of brain 5HT through alterations in tryptophan availability does not influence aggression in normal males as measured by the Buss task.     

Various relationships between predatory dominance and aggressive behavior in Pairs of cats

The experiments were performed on adult male cats selected initially as good mousekillers. Cats were tested in pairs and each pair was introduced separately to the experimental compartment. The attitude toward the partner before and during the predatory competition test as well as superiority in catching and killing the mice, considered as an index of dominance, were registered. In the course of experiment five types of relations between the predatory dominance and aggressive behavior were observed. The concept of dominance as an outcome of several factors was discussed. It was concluded that predatory dominance is not based exclusively on aggressive mechanisms, as it may be formed and sustained without overt aggression.     

A maximum likelihood method for latent class regression involving a censored dependent variable

The standard tobit or censored regression model is typically utilized for regression analysis when the dependent variable is censored. This model is generalized by developing a conditional mixture, maximum likelihood method for latent class censored regression. The proposed method simultaneously estimates separate regression functions and subject membership in K latent classes or groups given a censored dependent variable for a cross-section of subjects. Maximum likelihood estimates are obtained using an EM algorithm. The proposed method is illustrated via a consumer psychology application.