Differential Genetic and Environmental Influences on Reactive and Proactive Aggression in Children

While significant heritability for childhood aggression has been claimed, it is not known whether there are differential genetic and environmental contributions to proactive and reactive forms of aggression in children. This study quantifies genetic and environmental contributions to these two forms of aggression in an ethnically diverse urban sample of 9–10 year old twins (N = 1219), and compares results across different informants (child self-report, mother, and teacher ratings) using the Reactive–Proactive Aggression Questionnaire (RPQ). Confirmatory factor analysis of RPQ items indicated a significant and strong fit for a two-factor proactive–reactive model which was significantly superior to a one-factor model and which replicated across gender as well as the three informant sources. Males scored significantly higher than females on both self-report reactive and proactive aggression, findings that replicated on mother and teacher versions of the RPQ. Asian–Americans scored lower than most ethnic groups on reactive aggression yet were equivalent to Caucasians on proactive aggression. African–Americans scored higher than other ethnic groups on all measures of aggression except caregiver reports. Heritable influences were found for both forms of aggression across informants, but while boys’ self-reports revealed genetic influences on proactive (50%) and reactive (38%) aggression, shared and non-shared environmental influences almost entirely accounted for girls’ self-report reactive and proactive aggression. Although genetic correlations between reactive and proactive aggression were significant across informants, there was evidence that the genetic correlation was less than unity in boys self reported aggression, indicating that genetic factors differ for proactive and reactive aggression. These findings provide the first evidence for varying genetic and environmental etiologies for reactive and proactive aggression across gender, and provide additional support for distinction between these two forms of aggression.     

Children's false memory and true disclosure in the face of repeated questions

The current study was designed to investigate children's memory and suggestibility for events differing in valence (positive or negative) and veracity (true or false). A total of 82 3- and 5-year-olds were asked repeated questions about true and false events, either in a grouped order (i.e., all questions about a certain event asked consecutively) or in a nongrouped order (i.e., questions about a certain event were interspersed with questions about other events). Interviewer gender was also varied. Individual differences, including attachment style, inhibition, and behavioral adjustment, were examined as potential predictors of memory and suggestibility. Results revealed significant age, valence, and veracity effects on children's memory reports. Path analysis demonstrated that individual differences in behavioral problems and inhibitory ability predicted children's provision of inaccurate information. Implications for psychological theory and legal application are discussed.     

RPE at relative intensities after 12 weeks of resistance-exercise training by older adults

The constant-RPE tracking model monitors progress over the course of exercise training. During aerobic exercise, prior work using this model has demonstrated similar relative intensities pre- and posttraining, while the absolute workload increases posttraining. However, the prediction equation associated with these changes has not been examined during resistance training. 22 men and 27 women (M age 64 yr.) participated in a 12-wk. resistance training. Orientation determined resistances associated with RPEs of 4, 5-6, 7-8, and 9 on the OMNI-Resistance Exercise Scale for each of seven exercises for each participant. Individuals trained 3 days a week for 12 wk. Linear regression was used to calculate percent of 1-repetition maximum (%1-RM) at RPE 4, 6, and 8 for the exercises. Paired sample t tests, comparing pre- and posttraining %1-RMs at each RPE, indicated that posttraining %1-RMs were higher for RPE 4 and 6 for each exercise, while at RPE 8, results were significant for only 3 exercises. Thus for at least the RPE 4 and 6, the constant RPE tracking model is appropriate for resistance exercise; however, the equation of prediction appears to differ from that for aerobic exercise. Development of a new prediction equation may be necessary to track relative strength in older adults.     

Quality child care supports the achievement of low-income children: Direct and indirect pathways through caregiving and the home environment

Existing studies of child care have not been able to determine whether higher quality child care protects children from the effects of poverty, whether poverty and lower quality child care operate as dual risk factors, or whether both are true. The objective of the current study was to test two pathways through which child care may serve as a naturally occurring intervention for low-income children: a direct pathway through child care quality to child outcomes, and an indirect pathway through improvements in the home environment. Children were observed in their homes and child care settings at 6, 15, 24, and 36 months. An interaction between family income-to-needs ratio and child care quality predicted School Readiness, Receptive Language, and Expressive Language, as well as improvements in the home environment. Children from low-income families profited from observed learning supports in the form of sensitive care and stimulation of cognitive development, and their parents profited from unobserved informal and formal parent supports. Policy implications are discussed.     

Sexism, Hostility toward Women, and Endorsement of Beauty Ideals and Practices: Are Beauty Ideals Associated with Oppressive Beliefs?

Relationships between the endorsement of Western beauty ideals and practices and measures of hostility toward women and sexism were studied in 159 college men and 194 college women. The participants were predominately 18 or 19 years of age and of European American ethnicity. Correlations were computed between five factor analytically derived measures of beauty ideals and practices, two measures of the thin body ideal, and the following measures: Hostility toward Women Scale (HTWS; Lonsway & Fitzgerald, 1995), Attitudes toward Women Scale (AWS; Spence & Helmreich, 1978), and the two subscales of the Ambivalent Sexism Inventory (ASI; Glick & Fiske, 1996): hostile sexism (ASI-H) and benevolent sexism (ASI-B). It was found that endorsement of Western beauty ideals and practices was associated with hostility toward women, traditional sexism, hostile sexism, and, to a lesser extent, benevolent sexism. Results support feminist critiques of beauty practices as oppressive.     

SEXUAL OR FRIENDLY? ASSOCIATIONS ABOUT WOMEN, MEN, AND SELF

Using explicit, self-report measures, past research has found that heterosexual men, relative to heterosexual women, often attribute more sexuality to women's behaviors. In the present studies, the Implicit Association Test was used to determine if these findings held at the automatic processing level. The results of Study 1 were consistent with past research: Men, compared to women, had more sexual and less friendly automatic associations with the concept of women. Gender differences, however, were not observed in associations with the concept of self or men. Study 2 investigated how exposure to a dating context affected these associations. Associations about the self became more sexualized after reading about a first date, regardless of the participants' gender. However, for opposite-sex others, men's associations became less sexualized whereas women's associations became more sexualized. Collectively, these studies shed light on chronic and temporarily activated automatic processes relevant to sexual perception and contexts in which women are oversexualized.     

Molecular Genetic Studies of Eating Disorders: Current Status and Future Directions

ABSTRACT— We review association studies that have examined the genetic basis of eating disorders. Overall, findings suggest that serotonin, brain-derived neurotrophic factor, and estrogen genes may be important for the development of the disorders. These neuronal systems influence behavioral and personality characteristics (e.g., anxiety, food intake) that are disrupted in eating disorders. Future studies would benefit from larger sample sizes and inclusion of behavioral and personality covariates in analyses. Consideration of the mechanisms of genetic effects and interactions between genes and environment is also needed to extend conceptualizations of the genetic basis of these disorders.     

Genetic and environmental bases of childhood antisocial behavior: a multi-informant twin study

Genetic and environmental influences on childhood antisocial and aggressive behavior (ASB) during childhood were examined in 9- to 10-year-old twins, using a multi-informant approach. The sample (605 families of twins or triplets) was socioeconomically and ethnically diverse, representative of the culturally diverse urban population in Southern California. Measures of ASB included symptom counts for conduct disorder, ratings of aggression, delinquency, and psychopathic traits obtained through child self-reports, teacher, and caregiver ratings. Multivariate analysis revealed a common ASB factor across informants that was strongly heritable (heritability was .96), highlighting the importance of a broad, general measure obtained from multiple sources as a plausible construct for future investigations of specific genetic mechanisms in ASB. The best fitting multivariate model required informant-specific genetic, environmental, and rater effects for variation in observed ASB measures. The results suggest that parents, children, and teachers have only a partly "shared view" and that the additional factors that influence the "rater-specific" view of the child's antisocial behavior vary for different informants. This is the first study to demonstrate strong heritable effects on ASB in ethnically and economically diverse samples.     

The validity of using prior ratings of perceive exertion to regulate resistance exercise intensity

This investigation examined the validity of using ratings of perceived exertion (RPE) to regulate intensity during resistance exercise. 19 male (M age = 22.2 yr., SD = 2.7) and 19 female (M age = 21.4 yr., SD = 2.3) participants estimated exertion when performing the knee extension at 40% to 90% of one-repetition maximum. One week later, participants were asked to produce weights for the knee extension that elicited the feelings of exertion associated with 9, 13, and 17 on the Borg RPE scale. The weight produced at 9, 13, and 17 during the production session was compared to the weight lifted at each RPE during the estimation session. The effect sizes associated with the differences in weight lifted across sessions at each RPE were generally small in magnitude, especially at the higher intensities (ES = .40, -.09, .15, respectively). The results of this investigation support the use of RPE as a method of prescribing the intensity of resistance exercise.     

Brief experimental analysis of early reading interventions

The purpose of this study was to investigate how brief experimental analyses (BEAs) could be used to identify effective interventions for Kindergartners (2 girls and 2 boys, 5 years and 7-10 months old) with low performance and/or growth slope in letter sound fluency (LSF). Interventions were tested within a multielement design with brief mini-reversals until an intervention yielding at least 20% improvement on a specific subskill measure or a curriculum-based measure of LSF was identified. BEA-identified interventions were implemented one-on-one for 5 to 9 weeks. A multiple-baseline design across participants showed large intervention effects (average adjusted d = 2.4) on general outcome measures, supporting treatment validity of BEAs. Findings extend the BEA literature to younger participants, early reading interventions, and early reading measures.