Reducing stereotype threat in order to facilitate learning

Recent stereotype threat research has demonstrated that negative stereotypes about women's math ability can impair their mathematical learning. This experiment extends this research by examining whether presenting “gender fair” information can reduce learning decrements (on a focal and transfer task) and if the timing of this information matters. Women (N = 140) and men (N = 60) were randomly assigned to one of four conditions: control, stereotype threat only, stereotype threat removed before learning, and stereotype threat removed after learning. Compared with women in the control condition and women who had stereotype threat removed before learning, learning and transfer were poorer for women in the stereotype threat only condition and women who had stereotype threat removed after learning but before learning assessment. Men's learning and transfer were unaffected by condition. These findings suggest that a manipulation that can reduce performance deficits can also reduce learning decrements if it is presented before learning occurs. Copyright © 2011 John Wiley & Sons, Ltd.     

Is the Continuity of Externalizing Psychopathology the Same in Adolescents and Middle–Aged Adults? A Test of the Externalizing Spectrum’s Developmental Coherence

Externalizing psychopathology (EXT) is a framework for understanding diagnostic comorbidity and etiology of antisocial and substance-use behaviors. EXT indicates continuity in adulthood but the structure of adolescent EXT is less clear. This report examines whether adolescent EXT is trait-like, as has been found with adults, or categorical. We use tests of measurement invariance to determine how diagnostic indicators of EXT differ in adolescents compared to adults. The EXT measures employed were DSM-IIIR diagnoses of adult antisocial behavior, conduct disorder, and alcohol, marijuana, and drug dependence. Latent trait, latent class, and hybrid models were fit to two separate data sets: 2,769 seventeen-year-old adolescents and 2,619 adults from the Minnesota Twin Family Study. The best model in both samples was a single-trait LT model. Parameters from the adolescent and adult models were equivalent for all disorders except alcohol dependence. It appears that EXT in adolescence can be accurately represented by a single-trait model, and the measurement properties of EXT are similar during these time periods with the exception of alcohol dependence.     

Cumulative Effects of Mothers’ Risk and Promotive Factors on Daughters’ Disruptive Behavior

Little is known about the ways in which the accumulation of maternal factors increases or reduces risk for girls' disruptive behavior during preadolescence. In the current study, maternal risk and promotive factors and the severity of girls' disruptive behavior were assessed annually among girls' ages 7-12 in an urban community sample (N?=?2043). Maternal risk and promotive factors were operative at different time points in girls' development. Maternal warmth explained variance in girls' disruptive behavior, even after controlling for maternal risk factors and relevant child and neighborhood factors. In addition, findings supported the cumulative hypothesis that the number of risk factors increased the chance on girls' disruptive behavior disorder (DBD), while the number of promotive factors decreased this probability. Daughters of mothers with a history of Conduct Disorder (CD) were exposed to more risk factors and fewer promotive factors compared to daughters of mothers without prior CD. The identification of malleable maternal factors that can serve as targets for intervention has important implications for intergenerational intervention. Cumulative effects show that the focus of prevention efforts should not be on single factors, but on multiple factors associated with girls' disruptive behavior.     

A Prospective Longitudinal Study of Shyness from Infancy to Adolescence: Stability, Age-Related Changes, and Prediction of Socio-Emotional Functioning

This longitudinal, population-based and prospective study investigated the stability, age-related changes, and socio-emotional outcomes of shyness from infancy to early adolescence. A sample of 921 children was followed from ages 1.5 to 12.5?years. Parent-reported shyness was assessed at five time points and maternal- and self-reported social skills and symptoms of anxiety and depression were assessed at age 12.5?years. Piecewise latent growth curve analysis was applied, with outcomes regressed on latent shyness intercept and slope factors. Results showed moderate stability and increasing levels of shyness across time, with more variance and a steeper increase in early as compared to mid-to-late childhood. Both stable shyness and increased shyness in mid-to-late (but not early) childhood predicted poorer social skills and higher levels of anxiety and depression symptoms in early adolescence. The implications of the evidence for two developmental periods in shyness trajectories with differential impact on later socio-emotional functioning are discussed.     

Referential coding contributes to the horizontal SMARC effect

The present study tested whether coding of tone pitch relative to a referent contributes to the correspondence effect between the pitch height of an auditory stimulus and the location of a lateralized response. When left-right responses are mapped to high or low pitch tones, performance is better with the high-right/low-left mapping than with the opposite mapping, a phenomenon called the horizontal SMARC effect. However, when pitch height is task irrelevant, the horizontal SMARC effect occurs only for musicians. In Experiment 1, nonmusicians performed a pitch discrimination task, and the SMARC effect was evident regardless of whether a referent tone was presented. However, in Experiment 2, for a timbre-judgment task, nonmusicians showed a SMARC effect only when a referent tone was presented, whereas musicians showed a SMARC effect that did not interact with presence/absence of the referent. Dependence of the SMARC effect for nonmusicians on a reference tone was replicated in Experiment 3, in which judgments of the color of a visual stimulus were made in the presence of a concurrent high- or low-pitched pure tone. These results suggest that referential coding of pitch height is a key determinant for the horizontal SMARC effect when pitch height is irrelevant to the task.     

Interval, blocking, and marking effects during the development of schedule-induced drinking in rats

Schedule-induced drinking (SID) can occur when food-deprived rats are given access to water while receiving pellets on an intermittent reinforcement schedule. These conditions can increase water intake excessively. The possible role of adventitious reinforcement of postpellet drinking was assessed by testing whether response-reinforcer contiguity, the relative predictiveness of a response, and whether it is marked are important in the development of SID. Rats exposed to a short interpellet interval acquired SID most rapidly, with this acquired drinking response maintained when animals were transferred to a longer interpellet interval, thus indicating an easy-to-hard effect (Experiment 1). Further experiments demonstrated that a stimulus (a brief-flashing house light) occurring prior to pellet delivery could block the acquisition of SID (Experiment 2), while a lick-contingent tone, intended to increase the associability of this response, produced more rapid acquisition of SID (Experiment 3). Analysis of lick distributions revealed that licking became concentrated in the first half of an interpellet interval only after several sessions. Overall, the results indicated that similar factors affect the acquisition of both SID and instrumental conditioning with delayed reinforcement, as is consistent with a superstitious conditioning account of SID development.     

Altruistic punishment as an explanation of hunter-gatherer cooperation: how much has experimental economics achieved?

The discovery of the altruistic punishment mechanism as a replicable experimental result is a genuine achievement of behavioural economics. The hypothesis that cooperation in hunter-gatherer societies is sustained by altruistic punishment is a scientifically legitimate conjecture, but it must be tested against real-world observations. Guala's doubts about the evidential support for this hypothesis are well founded.     

Emotional Expression and Language: A Longitudinal Study of Typically Developing Earlier and Later Talkers from 15 to 30 Months

Children's emotional expression and language both develop during infancy and early childhood, yet these two communication systems have been studied primarily in isolation. This study focuses instead on assessing the relation between them just as productive language emerges during toddlerhood. Seventy‐seven typically developing, firstborn toddlers and their families were recruited at 13 months of age. Using an extreme groups design, earlier and later talkers were selected based on their MacArthur Communicative Development Inventory production scores. Laboratory visits occurred at 15, 21, and 30 months; home visits occurred at 3‐month intervals from 15 to 30 months. Observational and parent report measures assessed child language, emotional expression, temperament, and overall developmental functioning. Parents also reported on parenting stress and family life events. Overall, results support a significant relation between emotional expression and productive language that varies according to the specific emotion, a finding that may resolve earlier contradictory results in this area. Earlier talkers expressed more joy/pleasure than did later talkers, but later talkers expressed more fear and anger than did earlier talkers. Potential contributions of various child/family factors were explored. Child temperament is proposed as influencing this relation through its effects on the child's transactions with the caregiving environment.