Femininity and fertility in sisters with twin brothers: prenatal androgenization? Cross-sex socialization?

Are sisters of twin brothers behaviorally or physiologically masculinized? Prenatal exposure to their brothers' androgens and postnatal socialization experiences unique to girls growing up with twin brothers might influence their attitudes, pubertal development, and reproductive histories. To investigate, we studied age- and cohort-matched samples of Finnish sisters from same-sex and opposite-sex twin pairs. Using data from two ongoing longitudinal studies of consecutive birth cohorts of Finnish twins, we assessed pubertal development at ages 11 and 14 and endorsement of attitudes associated with femininity at age 16. We also studied fertility in Finnish women from same- and opposite-sex twin pairs born from 1958 through 1971, obtaining information on their child-bearing histories when they were ages 15 to 28. Results of each comparison were unambiguously negative: There was no evidence of differences between sisters from same- and opposite-sex twin pairs, and thus, no evidence of either androgenization or cross-sex socialization.     

Analyses of habituation in Caenorhabditis elegans

Although the nonassociative form of learning, habituation, is often described as the simplest form of learning, remarkably little is known about the cellular processes underlying its behavioral expression. Here, we review research on habituation in the nematode Caenorhabditis elegans that addresses habituation at behavioral, neural circuit, and genetic levels. This work highlights the need to understand the dynamics of a behavior before attempting to determine its underlying mechanism. In many cases knowing the characteristics of a behavior can direct or guide a search for underlying cellular mechanisms. We have highlighted the importance of interstimulus interval (ISI) in both short- and long-term habituation and suggested that different cellular mechanisms might underlie habituation at different ISIs. Like other organisms, C. elegans shows both accumulation of habituation with repeated training blocks and long-term retention of spaced or distributed training, but not for massed training. Exposure to heat shock during the interblock intervals eliminates the long-term memory for habituation but not the accumulation of short-term habituation over blocks of training. Analyses using laser ablation of identified neurons, and of identified mutants have shown that there are multiple sites of plasticity for the response and that glutamate plays a role in long-term retention of habituation training.     

the media's portrayal of urban and rural school violence: a preliminary analysis

Although the juvenile arrest rate has declined in the last few years, public awareness of juvenile crime has not diminished (Snyder 1996; Schiraldi 1998). The recent rash of rural school shootings has, in fact, heightened public awareness of juvenile crime and delinquent behavior. This research examines acts of school violence that have been committed by juveniles in three rural school districts and analyzes how the newspaper media present these acts relative to similar acts committed by juveniles in urban school settings. Our content analysis of the Wall Street Journal, Louisville Courier Journal, New York Times, St. Louis Post Dispatch, Los Angeles Times, and Washington Post reveals that these newspapers present school violence in these two settings very differently and that these differences are reflected in the way the political system reacts to such incidents.     

Self-Portraits: Possible Selves in European-American,Chilean, Japanese and Japanese-American Cultural Contexts

Possible selves of students from European-American (EA), Chilean (CH), Japanese-American (JA), and Japanese (JN) cultural contexts were analyzed, revealing differences in the emphasis given to various content themes. EA possible selves focus on intrapersonal themes (i.e., “fear being dependent”), consistent with cultural emphases on uniqueness and independent development. In JN, JA and CH contexts, career and education themes dominate possible selves, consistent with particularly strong cultural emphasis on professional and academic accomplishments. The cultural contexts also differ in their predominant configurations of possible selves—EA and CH possible selves often show balance (expected and feared selves of similar theme but opposing valence, i.e., “expect to graduate from college” and “fear dropping out of college”) while JN and JA selves more frequently match (expected and feared selves of similar thematic content and valence, i.e., “expect to be idle” and “fear being idle”).     

A Cautious Note on Auxiliary Variables That Can Increase Bias in Missing Data Problems

The treatment of missing data in the social sciences has changed tremendously during the last decade. Modern missing data techniques such as multiple imputation and full-information maximum likelihood are used much more frequently. These methods assume that data are missing at random. One very common approach to increase the likelihood that missing at random is achieved consists of including many covariates as so-called auxiliary variables. These variables are either included based on data considerations or in an inclusive fashion; that is, taking all available auxiliary variables. In this article, we point out that there are some instances in which auxiliary variables exhibit the surprising property of increasing bias in missing data problems. In a series of focused simulation studies, we highlight some situations in which this type of biasing behavior can occur. We briefly discuss possible ways how one can avoid selecting bias-inducing covariates as auxiliary variables.     

Impact of Abuse History on Adolescent African American Women's Current HIV/STD-Associated Behaviors and Psychosocial Mediators of HIV/STD Risk

This study examined if relationship power, sex refusal self-efficacy, or fear of condom negotiation mediated the relationship between abuse history and consistent condom use (CCU) among African American female adolescents (N?=?593). Participants with an abuse history (58%) were less likely to report CCU. Women with an abuse history reported less relationship power and self-efficacy for refusing sex and more fear of condom negotiation, none of which independently or jointly mediated the association between abuse and CCU. Notably, history of abuse was associated with CCU across mediator models despite inclusion of psychosocial mediators. This study demonstrates the importance of understanding adolescents' condom use behaviors within the context of their life experiences, especially past abuse history.     

Aptitude and Trait Predictors of Manned and Unmanned Aircraft Pilot Job Performance

Sixty-seven United States Navy maintainers (55 men and 12 women) representing both the aviation and surface communities participated in an experiment examining the efficacy of a simulation to assist technicians in rapidly understanding a system's state. Participants were assigned to one of three groups based on the technicians' experience and one of two experimental conditions: simulation (SIM) or technical manual (TM). The experimental task consisted of a series of eight questions regarding the condition of the S-3 aircraft's nose wheel steering (NWS) system given a set of initial aircraft conditions. To aid in performance of the experimental task, participants assigned to the TM condition were given a paper copy of the S-3 aircraft's organizational maintenance manual for the NWS system, and participants assigned to the SIM condition were given a laptop computer running a computer-based interactive model of the S-3 NWS system. Results showed that regardless of level of expertise, participants assigned to the SIM condition answered questions significantly faster than participants assigned to the TM condition. Further, technicians experienced in nonaviation maintenance assigned to the SIM condition answered questions significantly more accurately than experienced nonaviation technicians assigned to the TM condition.     

Personality Differences between Responsible and Less Responsible Children

Social maladjustment has been related to an external locus of control orientation. It was hypothesized, therefore, that delinquent females would be more external than a control sample. Further, since alienation from others is also associated with maladjustment, it was expected that the delinquents would also prefer greater distance from others. These hypotheses were confirmed with discussion being in terms of implication for rehabilitation of delinquents.     

Subjective Social Status and Well-Being: The Role of Referent Abstraction

Subjective social status (SSS) has been shown to predict well-being and mental health, above and beyond objective social status (OSS). However, little is known about the factors that moderate this relationship. Two studies explored whether the link between SSS and well-being varied depending upon the referent used for comparison in SSS judgments. Participants judged their well-being and SSS in comparison to referents that varied in abstraction. A confirmatory factor analysis on SSS judgments yielded two factors: (a) SSS perceptions toward global referents and (b) SSS perceptions toward local referents. SSS relative to a global referent was a better predictor of depression (Studies 1 and 2), life satisfaction (Studies 1 and 2), and self-esteem (Study 2) than SSS relative to a local referent. These findings have theoretical implications for understanding how people differentiate between local vs. global referents and practical implications for status-related health disparities.     

Do the Effects of Adolescent Employment Differ by Employment Intensity and Neighborhood Context?

Research on the effects of adolescent employment on primarily middle‐class youth suggests that intense employment, working more than 15 or 20 hours during the school year, is associated with increased participation in risky behavior. Despite these findings, scholars who focus on the development of youth living in low‐income urban areas often hypothesize that adolescent employment will have beneficial effects on this population. There is some evidence that adolescent employment is associated with increased educational achievement and adult employment for low‐income urban youth. The impact of adolescent employment on future engagement in risky behavior across levels of neighborhood deprivation and employment intensity was investigated on a sample of 1,057 adolescents from the Project on Human Development in Chicago Neighborhoods, a longitudinal study of neighborhood effects on development. After controlling for individual characteristics, intense employment during adolescence did predict increased use of cigarettes and alcohol and having a greater number of sexual partners 2 years after employment was measured. There were no significant interactions between neighborhood SES and adolescent employment status on involvement in risky behavior. These findings suggest that intense adolescent employment is associated with detrimental developmental outcomes for youth regardless neighborhood context.