The Undecidability of Propositional Adaptive Logic

We investigate and classify the notion of final derivability of two basic inconsistency-adaptive logics. Specifically, the maximal complexity of the set of final consequences of decidable sets of premises formulated in the language of propositional logic is described. Our results show that taking the consequences of a decidable propositional theory is a complicated operation. The set of final consequences according to either the Reliability Calculus or the Minimal Abnormality Calculus of a decidable propositional premise set is in general undecidable, and can be -complete. These classifications are exact. For first order theories even finite sets of premises can generate such consequence sets in either calculus.     

Cultural differences in the impact of social support on psychological and biological stress responses

Social support is believed to be a universally valuable resource for combating stress, yet Asians and Asian Americans report that social support is not helpful to them, resist seeking it, and are underrepresented among recipients of supportive services. We distinguish between explicit social support (seeking and using advice and emotional solace) and implicit social support (focusing on valued social groups) and show that Asians and Asian Americans are psychologically and biologically benefited more by implicit social support than by explicit social support; the reverse is true for European Americans. Our discussion focuses on cultural differences in the construal of relationships and their implications for social support and delivery of support services.     

“But Others Do It!”: Do Misperceptions of Schoolmate Alcohol and Marijuana Use Predict Subsequent Drug Use Among Young Adolescents?

We examined the effects of perceived prevalence of drug use among same-age peers on adolescents' subsequent drug use. In 7^th grade, participants estimated prevalence of alcohol and marijuana use among 7^th-grade students in their school, reported own use of these drugs, receipt of offers to use these drugs, and frequency of contact with peers who use these drugs. In 8^th grade, participants reported their frequency of alcohol and marijuana use. Although perceived prevalence of drug use predicted subsequent alcohol and marijuana use when controlling for actual prevalence, these effects disappeared once participants' prior levels of drug use and proximal peer contacts were considered. Implications of findings for intervention programs aiming solely to increase accuracy of perceived prevalence estimates are discussed.     

Rank and reproduction among female langur monkeys: Aging and improvement (They're not just getting older,they're getting better)

An investigation of the social rank, reproduction, and ages of adult female Indian gray langur monkeys (Presbytis entellus) living in two colony social groups revealed that rank based on displacements is neither correlated with nor best predicted by female age or reproductive value. The hierarchy of female ranks is best conceptualized as a layered ranking system in which there are clusters of females of the same dominance rank forming layers within the structure. Statistical significance in frequencies of displacement differs between but not within these layered groups of females. Factors such as group composition, presence of uterine kin, reproductive state, and individual personality are hypothesized to predict changes in female rank far better than does reproductive value. Our data show that reproductive success increases with age. The infant survival record for the six oldest females in our colony was much better than for the five youngest adult females.     

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.