School Context and Genetic Influences on Aggression in Adolescence

Genetic and environmental contributions to variation in aggression were examined using adolescents' self-reports of aggressive behavior. The National Longitudinal Study of Adolescent Health provided a sample of 1,515 pairs of adolescents in five genetically informative groups (i.e., monozygotic twins, dizygotic twins, full siblings, half siblings, and unrelated siblings reared together). The analysis, a DeFries-Fulker regression within a hierarchical linear model, yielded findings on individual-level heritability (h2), shared environmental effects (c2), school-level effects, and school-level moderation of h2 and c2. The estimate of h2 for aggression in the full sample was .32, and c2 was .05. In the moderating effect, h2 increased and c2 decreased with greater school-level family warmth. Two effects on school means were found: Those schools with greater ethnic-racial heterogeneity had higher mean levels of aggression, and schools where students perceived greater family warmth had lower mean levels of aggression.     

Ambiguous novel compounds and models of morphological parsing.

This paper reports on two experiments that investigated the activation of morphemes in English novel compounds. All experiments employed stimuli that we have called "ambiguous novel compounds." These words (e.g., clamprod) have two interpretable parses (e.g., clam + prod or clamp + rod) and thus offer an opportunity to investigate which parses are preferred, whether both possible parses are computed, and whether parsing procedures "divide" words into their morphological constituents or "extract" constituent representations. The results suggest that morphological parsing does not simply divide a word into its constituents, but rather generates multiple representations that are subsequently evaluated.     

Minority Influence,Social Change,and Social Stability

From Moscovici (Social influence and social change. London, Academic Press; 1976) on, a growing body of research on minority influence has been conducted within the social psychology mainstream. A general guideline of most of the research on this topic associates minority influence with social change and innovation. Minorities have been considered as challengers to social stability, and their dynamics have been considered in relation to the mechanisms through which social changes occur and established norms are modified and evolve in human society. In the present paper, we try to extend this viewpoint by suggesting that it represents only one side of a much more complex story. We consider the conditions under which minorities produce social change as well as the conditions under which they are, instead, inclined to defend the status quo. We then suggest that an integrative account of different approaches – namely, social identity, social dominance, and system justification – might contribute to expanding the theoretical frame of minority influence.     

Air pollution, cognitive deficits and brain abnormalities: a pilot study with children and dogs

Exposure to air pollution is associated with neuroinflammation in healthy children and dogs in Mexico City. Comparative studies were carried out in healthy children and young dogs similarly exposed to ambient pollution in Mexico City. Children from Mexico City (n: 55) and a low polluted city (n:18) underwent psychometric testing and brain magnetic resonance imaging MRI. Seven healthy young dogs with similar exposure to Mexico City air pollution had brain MRI, measurement of mRNA abundance of two inflammatory genes cyclooxygenase-2, and interleukin 1 beta in target brain areas, and histopathological evaluation of brain tissue. Children with no known risk factors for neurological or cognitive disorders residing in a polluted urban environment exhibited significant deficits in a combination of fluid and crystallized cognition tasks. Fifty-six percent of Mexico City children tested showed prefrontal white matter hyperintense lesions and similar lesions were observed in dogs (57%). Exposed dogs had frontal lesions with vascular subcortical pathology associated with neuroinflammation, enlarged Virchow-Robin spaces, gliosis, and ultrafine particulate matter deposition. Based on the MRI findings, the prefrontal cortex was a target anatomical region in Mexico City children and its damage could have contributed to their cognitive dysfunction. The present work presents a groundbreaking, interdisciplinary methodology for addressing relationships between environmental pollution, structural brain alterations by MRI, and cognitive deficits/delays in healthy children.