The Association Between Internalizing and Externalizing Behavior in Childhood and Early Adolescence: Genetic or Environmental Common Influences?

This study analyzed the genetic and environmental influences on internalizing and externalizing behavior problems and the nature of their cooccurrence in a national Norwegian twin sample. The sample comprised 526 identical and 389 fraternal same-sexed twin pairs from five birth cohorts, aged 5-6, 8-9, 12-13, 13-14, and 14-15 years. Behavior problems were assessed by parental ratings on the Child Behavior Checklist. A model of additive genetic, shared, and nonshared environmental influences was fitted to both internalizing and externalizing behavior in four sex and age groups. The considerable covariance,r = .51 to .58, between these traits is accounted for mainly by common environmental components; this effect was most marked in the 5 to 9-year olds. Concordance rates for children scoring above 1 standard deviation from the total sample mean on the internalizing scale only, externalizing scale only, or both indicated stronger genetic influences for internalizing or externalizing problems only than for combined problems.     

Implicit and explicit tests of odor memory reveal different outcomes following interference

Experiencing two odors as a mixture can later increase their perceived similarity when presented separately. Such an increase in similarity can be used as an implicit measure of how well participants remember the mixture. Three experiments tested the resistance to interference of this effect by first giving participants exposure to two 2-odor mixtures and then presenting each odor from one mixture (interfered pair) separately many times. After the latter interference phase, participants rated the similarity of the two odors in each pair. The experiments varied in terms of the number of initial exposures to the mixtures, the number of odor presentations in the interference phase, and the control conditions employed. No difference in similarity ratings for the interfered and non-interfered pair was found in any experiment. In contrast to the lack of interference with this implicit measure, an explicit measure of memory based on participants’ ratings of odor frequency revealed that they could recall to some degree that the interfered odors had been presented alone in the second phase. These results suggest that implicit memory for odor mixtures is highly resistant to interference and is consistent with a configural encoding account of this effect.     

Gender Differences in Interest and Knowledge Acquisition: The United States,Taiwan, and Japan

The relationship between interest and knowledge was investigated in a representative sample of 11th grade students from cultures that differ in the strength of their gender-role stereotypes and their endorsement of effort-based versus interest-based learning. Among 11th graders from the United States (N = 1052), Taiwan (N = 1475), and Japan (N = 1119), boys preferred science, math, and sports, whereas girls preferred language arts, music, and art. General information scores were comparable across the three locations; however, boys consistently outscored girls. Gender and interest in science independently predicted general information scores, whereas gender and interest in math independently predicted mathematics scores. Cultural variations in the strength of the relationship between gender, interest, and scores indicate that specific socialization practices can minimize or exaggerate these gender differences.     

Race Shapes Perceptions of Juvenile Offenders in Criminal Court1

We investigated the effects of defendant race, victim race, and juror gender on non‐African American mock jurors' perceptions of crimes committed by juvenile offenders. We predicted that mock jurors, particularly men, would render more pro‐prosecution case judgments when the defendant was African American than White. We also predicted that defendants would be judged more harshly when the crime victim was portrayed as White rather than as African American. Although there were few main effects of defendant race or victim race on case judgments, defendant and victim race by juror gender interactions revealed that men (but not women) demonstrated the predicted bias against African American defendants and victims. Explanations and implications are discussed.     

The role of experience in liking "read-to-drink" alcoholic beverages.

Ready-to-drinks (RTDs) are composed of an alcoholic component and a soft-drink base and are primarily consumed by a youth market. The authors explored whether liking and experience with an RTD soft-drink base predicts liking for the RTD. Participants (N=350) from ages 12 to 30 years sampled 3 RTDs and their respective soft-drink and alcoholic components. For milk- and fruit-based RTDs, liking for and familiarity with their soft-drink base was the best predictor of liking for and familiarity with the RTD itself. For the Coke-based RTD, familiarity with and liking for bourbon best predicted familiarity with and liking for the RTD. All of these effects were consistent across blind and nonblind testing. The authors' results suggest that where there is perceptual similarity between the RTD and its soft-drink base, these beverages may provide an easy transition into alcohol consumption for novice drinkers.     

Dehumanizing but competent: The impact of gender,illness type,and emotional expressiveness on patient perceptions of doctors

This study is the first attempt to investigate men's and women's anticipated reactions to a consultation with a doctor holding either a dehumanizing or humanistic approach to patient treatment. Participants (N = 375) read a vignette depicting a doctor's treatment philosophy—emphasizing either the metaphor of the body as a machine (dehumanizing condition) or emphasizing individual humanness (humanizing condition). They then imagined consulting the doctor about a psychological or physical illness. Although, medical dehumanization had undesirable consequences, some men rated the dehumanizing doctor as more competent than the humanizing doctor. These were men who were (a) emotionally expressive and seeking help for a psychological illness, and (b) men low in emotional expressiveness seeking help for a physical illness.     

Binocular shape constancy from novel views: the role of a priori constraints

We tested shape constancy from novel views in the case of binocular viewing, using a variety of stimuli, including polyhedra, polygonal lines, and points in 3-D. The results of the psychophysical experiments show that constraints such as planarity of surface contours and symmetry are critical for reliable shape constancy. These results are consistent with the results obtained in our previous psychophysical experiments on shape constancy from novel views in the presence of a kinetic depth effect (Pizlo & Stevenson, 1999). On the basis of these results, we developed a new model of binocular shape reconstruction. The model is based on the assumption that binocular reconstruction is a difficult inverse problem, whose solution requires imposing a priori constraints on the family of possible interpretations. In the model, binocular disparity is used to correct monocularly reconstructed shape. The new model was tested on the same shapes as those used in the psychophysical experiments. The reconstructions produced by this model are substantially more reliable than the reconstructions produced by models that do not use constraints. Interestingly, monocular (but not binocular) reconstructions produced by this model correlate well with both monocular and binocular performance of human subjects. This fact suggests that binocular and monocular reconstructions of shapes in the human visual system involve similar mechanisms based on monocular shape constraints.     

Examining the State-Trait Anxiety Relationship: A Behavioural Genetic Approach

State and trait anxiety define different aspects of anxiety, and may represent environmentally and genetically mediated components of this phenotype. Furthermore their relationship, where trait anxiety is expressed through levels of state anxiety under threatening circumstances, may represent a process of interplay between a genetic vulnerability factor and an environmental stressor. To test these hypotheses, we explored genetic and environmental influences on measures of state and trait anxiety in a sample of 1058 twins (521 males and 537 females) aged 8–16. The results were consistent with these hypotheses. State anxiety is largely influenced by environmental factors in males and females whereas trait anxiety shows moderate genetic effects and substantial non-shared environment effects. Their association was accounted for by non-shared environmental effects, with modest genetic and shared environmental inputs. The implications of these results for vulnerability mechanisms involving stress reactivity on anxiety are discussed.