The normative/descriptive gap is the discrepancy between actual reasoning and traditional standards for reasoning. The relationship between age and the normative/descriptive gap was examined by presenting adolescents with a battery of reasoning and decision-making tasks. Middle adolescents (N = 76) performed closer to normative ideals than early adolescents (N = 66), although the normative/descriptive gap was large for both groups. Correlational analyses revealed that (1) normative responses correlated positively with each other, (2) nonnormative responses were positively interrelated, and (3) normative and nonnormative responses were largely independent. Factor analyses suggested that performance was based on two processing systems. The "analytic" system operates on "decontextualized" task representations and underlies conscious, computational reasoning. The "heuristic" system operates on "contextualized," content-laden representations and produces "cognitively cheap" responses that sometimes conflict with traditional norms. Analytic processing was more clearly linked to age and to intelligence than heuristic processing. Implications for cognitive development, the competence/performance issue, and rationality are discussed.

Theory-motivated reasoning biases arise when different reasoning skills are invoked to evaluate evidence that is congruent or incongruent with individuals' belief systems. To explore this phenomenon, 66 early and 73 middle adolescents evaluated evidence relevant to their theories of social class or religion. In both conditions, reasoning biases were found, but in-group biases were evident only in the religion condition. In both conditions, higher order scientific reasoning was used to reject theory-incongruent evidence and judgmental heuristics (i.e., cognitive rules of thumb) were used to evaluate theory-congruent evidence. In both conditions, subsequent to the evidence presentation, adolescents' theories became more extreme (i.e., polarized) than at the outset of the experiment. Beliefs regarding the origin, acquisition, and certainty of knowledge, however, appeared to moderate reasoning biases and theory polarization. Age differences emerged on only one index of bias: In the religion condition, middle adolescents were more likely to treat theory-incongruent evidence as implausible. These findings are pertinent to theories of cognitive development, decision making, rationality, and in-group favoritism.

Recent concerns with the increasing prevalence of overweight and obesity among children and adults indicate the need to better understand the psychosocial correlates of weight. We examined the relationships among negative stereotypes of obesity, "thin ideal" beliefs, perceptions of the causes of obesity and of control over weight, body esteem, and global self-esteem. A negative correlation between beliefs in control over one's weight and self-esteem was mediated by both negative attitudes toward obesity and thin idealization. Additionally, body esteem and gender were related but this relationship was mediated by beliefs in control over weight and valuation of the thin ideal. Central to the theoretical foundation of this research, however, was the observed negative correlation between negative attitudes toward obesity and self-esteem. This relationship was mediated primarily by the belief that obesity is caused by personality shortcomings. This last finding is explained from a social identity perspective.

Research on adult judgment and decision making has focused on deviations from normative models, demonstrating biases and reliance on heuristic shortcuts, thus presenting a very different picture than developmental theories that describe a unidirectional progression toward greater logic and efficiency. Recent research related to this apparent contradiction indicates that children develop competencies to reason effectively and make normative decisions, but also develop biased judgment strategies that are used inappropriately in some situations. We suggest potential explanations for the findings, highlighting the need to consider models that incorporate development in both experiential and analytic information processing systems.

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