Evidence for the Phase Transition from Rule I to Rule II on the Balance Scale Task

A central and recurrent theme in developmental psychology is the question whether development proceeds continuously or discontinuously. This question is difficult to answer because the two types of development may be hard to distinguish. To investigate whether change is discontinuous, one requires a formal model for discontinuous development. Such a model should provide operational, empirical criteria to investigate the nature of development. The cusp model, which is derived from catastrophe theory, is a formal model of discontinuity that provides such criteria. Eight criteria, so-called catastrophe flags, can be derived from the model. Some of these flags are predicted in other models of discontinuity, but others, notably hysteresis, are unique to catastrophe theory. In the present research, it is tested whether the transition from Rule I to Rule II on the balance scale task proceeds discontinuously. The present research centers around five catastrophe flags: bimodality, inaccessible region, sudden jump, divergence, and hysteresis. Two experiments are reported. In Experiment 1, a paper-and-pencil version of the balance scale task was administered to 314 children who were 6 to 10 years old. In Experiment 2, an adapted version of the test was administered to 302 children who were 6 to 10 years old. Bimodality, inaccessible region, hysteresis, and sudden jump were clearly observed. Divergence was not observed. The presence of four of the five flags strongly supports the hypothesis that the transition from Rule I to Rule II is discontinuous.     

Comprehension of algebraic expressions by experienced users of mathematics

Little is known about how people comprehend mathematical expressions. In the present study we investigate the internal representations used by experienced users of mathematics to encode algebraic expressions. Initially, a memory recognition task was conducted that examined the role of mathematical syntax in the encoding of algebraic expressions. The results indicate that participants could more readily identify those parts of a previously seen expression that were syntactically well formed than those that were not well formed, suggesting that syntax plays an important role. To determine the level of syntactic structure involved, a second recognition task was conducted. The results indicate that algebraic expressions are encoded into components that represent the phrasal constituents of the expression. However, the results of these experiments did not rule out the possibility that the visual processes of perceptual organization were used to encode the expressions, or that the data were a consequence of a mathematical “lexicon” of common mathematical “phrases”. Three further experiments were conducted to examine this, the results of which indicate that the encoding of algebraic expressions is based primarily on processes that occur beyond the level of visual or “lexical” processing. This is consistent with our finding that syntactic structure plays a key role.     

The Social Capital of Blacks and Whites: Differing Effects of the Mass Media in the United States

This study relied on telephone survey interviews of adults in two U.S. metropolitan areas to examine whether the relationship between mass media use and social capital varies according to ethnicity. A multigroup approach taken with structural equation modeling validates a four‐factor model of social capital for Blacks and Whites and then, with the implementation of a comprehensive model that also includes mass media inputs, tests for structural variance between the ethnic groups. A well‐fitting comprehensive model is achieved, with significant differences between Blacks and Whites in terms of the mass media use structures. In support of the two hypotheses, the relationship between news use and social capital is less positive for Blacks than for Whites and the relationship between entertainment TV viewing and social capital is more negative for Blacks than for Whites. These findings are discussed in terms of literature involving mass media effects on social capital, news coverage of ethnic groups, and ethnic differences in self‐conceptualization and media responses.     

The influence of juggling on mental rotation performance in children with spina bifida

This study examined the influence of juggling training on mental rotation ability in children with spina bifida. Children between the ages of 8 and 12 solved a chronometric mental rotation test. Half of the children received juggling training (EG) over an 8week time period; the other half did not receive training (CG). Afterwards, all participants completed the mental rotation test again. Children of the EG showed a significant decrease in reaction time and an increase in mental rotation speed compared to the control group. This indicates that juggling improves the rotation in the mental rotation process in children with spina bifida.     

Effects of sad mood on time-based prospective memory

Very little is known about the influence of emotional factors on prospective memory (PM) performance. We used a mood induction (neutral or sad) to examine the effects of sad mood on time-based PM performance. Based on Ellis and Ashbrook's (1988) resource allocation model, we hypothesised an adverse effect of sad mood on PM performance. Results revealed that participants who responded to the sad mood induction procedure showed reduced PM performance that mainly resulted from a decreased timeliness of PM responses, but only in the first half of the task. Mood effects on PM could be explained in terms of reduced and less accurate monitoring. Implications for concepts of PM and the assessment of emotional after-effects are discussed.     

The mediated learning experience (MLE) in a three generational perspective

Previous research has shown that mediated learning experience (MLE) strategies are important for the development of cognitive skills. Theoretically, grandparents have a significant role in the intergenerational transmission of MLE strategies. The purpose of this study is to investigate the resemblances and unique characteristics of mothers' and grandmothers' MLE strategies. A sample of 52 Israeli families composed of mother–child and maternal grandmother–child dyads were videotaped at home in two conditions: free play and structured (the same child was observed in each dyad). The interactions were analysed using the observation of mediated interaction (OMI). Higher levels of MLE strategies were found during free play than in the structured condition. Positive correlations between grandmothers' and mothers' MLE strategies were found under both conditions. However, grandmothers provided a higher level of MLE strategies for intentionality and reciprocity, meaning, and transcendence, but less mediation of regulation of behaviour than mothers. It is concluded that these differences may be the result of either differences in the perceived roles of mothers and grandmothers, or differences in the levels of experience of mothers and grandmothers.