The overall purpose of this study was to explore the alcohol consumption patterns of adolescents by beverage type. A total of 705 primarily 9th grade students were recruited to participate in this study in the spring of 2002. Alcoholic beverage use differed significantly across gender and ethnicity on a number of beverage-specific drinking…

A pair of monozygotic twins discordant for symptoms of Asperger syndrome was evaluated at the age of 13.45 years using psychometric, morphometric, behavioural, and functional imaging methods. The lower-functioning twin had a smaller brain overall, a smaller right cerebellum, and a disproportionately large left frontal lobe, and manifested almost…

This study, based on constructivist learning theory, examined how effectively preservice chemistry teachers (N = 43) can be educated to think flexibly and to reorganize their thinking in a way that may complement diverse ways students approach the subject domain. The teacher's cognitive structure was assessed prior to and after a conceptual change…

The diverse life experiences of contemporary lesbians are shaped by women's differing ties to two social worlds, the majority heterosexual society and the minority subculture of the lesbian or sexual-minority world. This article presents a detailed conceptual analysis of a dual-identity framework that emphasizes lesbians' simultaneous affiliations…

This study examined the relation between the amount of mathematical input in the speech of preschool or day-care teachers and the growth of children's conventional mathematical knowledge over the school year. Three main findings emerged. First, there were marked individual differences in children's conventional mathematical knowledge by 4 years of…

Feedback is central to the development of effective learning, yet is comparatively underresearched. This article seeks to examine the notion of written feedback on assignments and argue that this feedback process is more complex than is sometimes acknowledged. The author illustrates the problematic nature of assignment feedback by drawing on a…

People categorized pairs of perceptual stimuli that varied in both category membership and pairwise similarity. Experiments 1 and 2 showed categorization of 1 color of a pair to be reliably contrasted from that of the other. This similarity-based contrast effect occurred only when the context stimulus was relevant for the categorization of the…

An ability-based guessing model is formulated and applied to several data sets regarding educational tests in language and in mathematics. The formulation of the model is such that the probability of a correct guess does not only depend on the item but also on the ability of the individual, weighted with a general discrimination parameter. By so…

In this article, the authors make an attempt to operationalize the notion of "identity" to justify the claim about its potential as an analytic tool for investigating learning. They define identity as a set of reifying, significant, endorsable stories about a person. These stories, even if individually told, are products of a collective…

Multilevel modeling allows for the simultaneous analysis of data gathered at more than 1 unit of analysis (e.g., children nested in schools). It is often used to examine the effects of various contexts on individual differences in change. This paper promotes the application of multilevel models to longitudinal dyadic data in family research. By…

The polysialylated neural cell adhesion molecule (PSA-NCAM) has been implicated in activity-dependent synaptic remodeling and memory formation. Here, we questioned whether training-induced modulation of PSA-NCAM expression might be related to individual differences in spatial learning abilities. At 12 h posttraining, immunohistochemical analyses…

This paper, based on naturalistic data, describes the acquisitional course and use of the articles "a" and "the" in young English-speaking children (18-61 months), with special emphasis on the role of individual variation. A growth modeling approach to the data reveals that children's individual acquisition schedules are similar in trend, but vary…

Objective: To compare personality traits of psychiatry residents with various characteristics. Method: The authors administered Cloninger's personality inventory to residents at two schools. Results: There were no trait differences between international medical graduates (IMGs) and U.S. medical graduates (USMGs) or those for whom psychiatry was a…

Structural, mean- and individual-level, differential, and positive personality continuity were examined in 599 patients treated for major depression assigned to 1 of 6 forms of a 6-month pharmacy-psychotherapy program. Covariation among traits from the Five Factor model remained invariant across treatment, and patients described themselves as…

A sense of direction (SOD) computes the body's facing direction relative to a reference frame grounded in the environment. The authors report on three experiments in which they used a heading-recall task to tap the functioning of a SOD system and then correlated task performance with self-reported SOD as a convergent test of the task's construct…