Infant temperament and performance on the Bayley Scales of Infant Development at 4, 8, and 12 months of age

Infants were assessed with the Rothbart Infant Behavior Questionnaire (an objective measure of infant temperament based on maternal reports) and the complete Bayley Scales of Infant Development (BSID) at 4, 8, and 12 months of age. Activity level was related to BSID performance at each age with babies who obtained higher scores rated as more active. Activity level was also related to the infants' behavior during the test administration at 8 and 12 months. A negative relation was found between smiling and laughter and the mental development index at 8 and 12 months. These data suggest that aspects of infant temperament as assessed by maternal report share a small amount of variance with BSID performance and the amount of shared variance increases with age.     

Marijuana use from adolescence to young adulthood: multiple developmental trajectories and their associated outcomes.

This study used latent growth mixture modeling to identify discrete developmental patterns of marijuana use from early adolescence (age 13) to young adulthood (age 23) among a sample of 5,833 individuals. After the a priori removal of abstainers, 4 trajectory groups were identified: early high users, who decreased from a relatively high level of use at age 13 to a more moderate level: stable light users, who maintained a low level of use: steady increasers, who consistently increased use; and occasional light users, who began use at age 14 and used at low levels thereafter. Analyses of covariance comparing the trajectory groups on behavioral, socioeconomic, and health outcomes at age 29 revealed that abstainers consistently had the most favorable outcomes, whereas early high users consistently had the least favorable outcomes.     

Reducing the tendency to self-handicap: The effect of self-affirmation

Self-handicapping, the creating or claiming of obstacles to one’s performance to influence explanations given for subsequent outcomes, has been shown to have a host of attitudinal and behavioral consequences. Given the wide ranging impact of self-handicapping, it is important to understand the conditions under which self-handicapping is more or less likely to occur. Accordingly, the present study tested the hypothesis that people will be less likely to engage in self-handicapping if they have previously engaged in self-affirmation. The results of this study found that self-affirmation was more effective in reducing self-handicapping behavior when individuals experienced non-contingent success than when they experience contingent success. Theoretical contributions to the self-handicapping and self-affirmation literatures are discussed, as are practical implications.