Multilevel models in developmental psychological research: Rationales and applications

The armoury of statistical techniques has recently been enhanced with the multilevel model for longitudinal data. The present article explains the multilevel model for longitudinal data to the statistically non-sophisticated reader. It shows how the model relates to the five rationales of longitudinal research, as they were put forward by Baltes and Nesselroade (1979). In addition, it shows how the model matches Wohlwill's methodology of developmental functions. To elucidate the model further, three applications are given. The applications pertain to the development of children's sleeping duration during the first 18 months of life, the effects of early hospitalization on the daily frequency of crying, and the developmental relationship between social and solitary play.     

Gender and health on the kibbutz

Gender differences in health status and illness behavior have been explained in terms of sex roles and gender-related personality traits. It may be hypothesized that in a community that is committed to gender-negating ideology, where men and women alike participate in public life, and housework and child care largely collectivized, gender health differences will disappear. The kibbutz movement is committed to the ideology of the emancipation of women: women fully participate in the labor force and decision making. Nonetheless, women on the kibbutz are responsible for the housework and are concentrated in feminine occupations. The kibbutz, then, allows us to test the relationship between gender ideology and participation in public life vs. gender roles and tasks, and health. The health behavior, health status, and illness behavior of 230 members of two kibbutzim, one religious and one secular, were studied. Men and women report similar health status and illness behavior; parental status is not related to health; and marital status is related to psychological distress only. Similar patterns were observed for the secular kibbutz and the religious one despite the more traditional division of labor in the latter.Medical student, supported by the National Fund for Medical Education, 35 Kneeland Street, Boston, MA 02111.     

Search behaviour of cats (Felis catus) in an invisible displacement test: cognition and experience

An invisible displacement test was administered to cats in order to test the hypothesis that search behaviour in this species is influenced by their limited capacity for object permanence as well as by their previous experience with the environment. Experiment 1 compared three groups of cats in a five-choice hiding task in which the hiding places could be discriminated by their spatial positions. Two groups received a visible displacement training before the invisible displacement test and one group did not. Experiment 2 compared two groups of trained subjects in the same task, but the hiding places could be discriminated by spatial and visual cues. The results confirmed that cats are unable to solve problems with invisible displacements. The visible displacement training improved their performance, but was not sufficient to make them succeed. Experience with the hiding potential of the covers also gives more persistence to search behaviour. Finally, the distribution of search attempts is not determined by the proximity to the target and is influenced only partially by the subjects' previous experience. Like Stage 5 infants, cats rely mainly on their immediate perception. They search for an object in the last location they have seen it disappear or under the nearest cover from this location.     

Racial Identity Development Among Gifted Black Students: Counseling Issues and Concerns

A review of the literature suggests that a paucity of information exists regarding how culture-specific issues such as being both Black and gifted influence the psychological needs and personality development of gifted Black students. Stellar attempts, however, are currently underway to develop theories and perspectives of racial identity development among Black students. These theories and perspectives are discussed in an attempt to understand and address the psychological and social needs of gifted Black students.     

Motor skill acquisition and retention as a function of average feedback, summary feedback, and performance variability

Summary feedback involves withholding feedback from subjects until the last trial in a block is completed, and then presenting feedback about each trial. A variation of this method, called average feedback (Young & Schmidt, 1992), presents subjects with only the mean of the trial block. We investigated whether these methods have similar effects on acquisition and retention of a simple motor skill. Five groups of subjects (n = 16 per group) performed 60 acquisition trials of an aiming task involving both spatial and temporal accuracy. We presented average and summary feedback based on either 5-trial blocks or 15-trial blocks and compared these schedules with every-trial feedback. During acquisition, all groups improved with practice, with a slight tendency for the every-trial condition to have less absolute error than the longer summary and average conditions. Analysis of delayed no-feedback retention tests, however, revealed a strong advantage for the 5-trial summary and average conditions compared with the every-trial condition. In addition, we found that for long blocks of acquisition trials without augmented feedback, the performance variability of those trials was associated with retention performance. Results are discussed in terms of how these different manipulations may make feedback less useful during acquisition, but foster the use of certain information processing activities that enhance overall learning.     

Risky aggression in individuals and groups.

This study set out to investigate whether the risky shaft found in group consensus decisions as compared to group members' personal decisions extends to situations that combine risk and aggression. In a between-subjects design, subjects were exposed, either alone or as members of unisex triads, to an experimental task in which the risk entailed severe noxious consequences. The findings show that for both sexes, groups take significantly greater risks than individuals even when risk taking is mediated by aggressive means. The results are seen and discussed as limiting the explanatory scope of the risk-as-a-value hypothesis and as more consistent with the diffusion of responsibility hypothesis.     

Achievement motivation among urban adolescents: Work hope, autonomy support, and achievement-related beliefs

Drawing upon expectancy value, hope, and self-determination theories, this study explores the contributions of work-based beliefs and autonomy support as predictors of adaptive achievement-related beliefs. Two hundred and one urban high school students who were enrolled in a work-based learning program completed measures of work hope, autonomy support, and achievement beliefs. Results from the full canonical correlation model revealed that work hope, career planning, and autonomy support shared 37.5% of the variance with achievement-related beliefs. Moreover, work hope and teacher autonomy support further contributed unique variance in explaining these beliefs. The findings contribute to the theoretical knowledge base concerning the value of work-based learning in fostering academic motivation among adolescents.     

The Stroop congruency effect is more observable under a speed strategy than an accuracy strategy

Naming the ink color of an incongruent color word (e.g., RED printed in green) usually takes longer than naming the ink color of a color bar. However, when the ink matches the word (e.g., RED printed in red), naming tends to be faster. These phenomena are known as the STroop interference effect and the Stroop congruency effect, respectively. Although the interference effect has been robust and reliable across studies, the congruency effect tends to be elusive. It was hypothesized that this variation in outcomes might be related to subjects' response strategy. The experiment conducted to test this hypothesis induced either a speed or an accuracy strategy in two separate groups of subjects. Significant interference effects were found for both groups and the magnitudes did not differ. At the same time, the congruency effect was observed in the speed group but not in the accuracy group. These results suggest that researchers who wish to observe and study the Stroop congruency and interference effects should place special emphasis on speed. Implications of the study for a model of the Stroop effect are also discussed.     

Effects of media violence on viewers' aggression in unconstrained social interaction

This article provides a meta-analytic review of the experimental effects of media violence on viewers' aggression in unstructured social interaction. In the reviewed experiments, children or adolescents were exposed to violent or control presentations and their postexposure behavior was coded for aggression during spontaneous social interaction. Exposure to media violence significantly enhanced viewers' aggressive behavior when the findings were aggregated across studies, but the effect was not uniform across investigations. Only suggestive evidence was obtained concerning moderators of the effect: Marginally stronger relations were obtained in those studies using a cross-section of the normal population of children (vs. emotionally disturbed children) and in those studies conducted in laboratory settings (vs. other contexts).