A 15-year longitudinal test of the theory of planned behaviour to predict physical activity in a randomized national sample of Canadian adults

BackgroundThere have been very limited long-term prospective studies examining social-cognitive models in the PA domain with large, representative population samples.ObjectiveThe primary objective was to examine the Theory of Planned Behaviour's (TPB) ability to explain PA behaviour in a randomly selected national sample of Canadian adults over a 15-year period. A secondary objective was to test the moderating effects of gender on TPB.DesignThe study employed a longitudinal design.MethodsA cohort of 1427 randomly-selected adults reported TPB constructs and PA behaviour in 1988, and again in 2003. Structural equation modelling techniques were employed to test TPB.ResultsThe full model including both 1988 and 2003 TPB measures accounted for 29% and 21% of the variance in intention, and 9% and 22% of the variance in PA in 1988 and 2003, respectively. Gender moderated aspects of the TPB in the full model. The core predictive model (1988 TPB constructs predicting 2003 PA behaviour) explained 13% of the variance in 2003 PA behaviour.ConclusionsThe TPB's long-term ability to predict PA behaviour is modest.     

Working memory and executive functions: effects of training on academic achievement

The aim of this review is to illustrate the role of working memory and executive functions for scholastic achievement as an introduction to the question of whether and how working memory and executive control training may improve academic abilities. The review of current research showed limited but converging evidence for positive effects of process-based complex working-memory training on academic abilities, particularly in the domain of reading. These benefits occurred in children suffering from cognitive and academic deficits as well as in healthy students. Transfer of training to mathematical abilities seemed to be very limited and to depend on the training regime and the characteristics of the study sample. A core issue in training research is whether high- or low-achieving children benefit more from cognitive training. Individual differences in terms of training-related benefits suggested that process-based working memory and executive control training often induced compensation effects with larger benefits in low performing individuals. Finally, we discuss the effects of process-based training in relation to other types of interventions aimed at improving academic achievement.     

Index for Volume 23

In this study, changes in movement coordination caused by fatigue that developed during repetitive lifting were examined. Five men performed 6 times a 5-min bout of lifting an 8-kg barbell at 15 lifts/min, using two lifting techniques; one minimized trunk rotation (squat lift), and the other minimized rotation in the knee joint (stoop lift). Kinematics and dynamics were studied by means of movement analysis and inverse dynamics, using a two-dimensional linked segment model. Within-subject variation over repetitive lifts of the time course of joint angles was smaller than between-subjects variation on the first analyzed lift. Relative timing between joint rotations did not change significantly across repetitive lifts, except between knee and hip in the squat lift. No change of the lumbosacral torque over repetitive lifts was found. The adaptability of the neural control appeared to be sufficient to accommodate the strong changes of the input-output characteristics of the muscles caused by fatigue so that an essentially constant performance of the movement act was maintained.     

Relationship of Adult Representations of Childhood Parenting and Personality Tendencies to Adult Stressors and Political Ideology

Undergraduate students in a Southeastern US University (n = 232) responded to an inventory that included retrospective measures of their parents’ style of parenting (authoritarian vs. authoritative) and their own childhood psychological tendencies (insecurity vs. confidence), as well as their adult stressors and political orientation. Authoritative parenting positively correlated with childhood confidence and negatively correlated with both childhood insecurity and adult stressors. Conversely, authoritarian parenting was positively associated with childhood insecurity and adult stressors but was not significantly correlated with childhood confidence. For the most part, parenting styles, early childhood tendencies, and adult stressors were unrelated to adult political ideology, contrary to previous longitudinal research reporting these connections.     

Monkeys represent others' knowledge but not their beliefs

The capacity to reason about the false beliefs of others is classically considered the benchmark for a fully fledged understanding of the mental lives of others. Although much is known about the developmental origins of our understanding of others' beliefs, we still know much less about the evolutionary origins of this capacity. Here, we examine whether non-human primates - specifically, rhesus macaques (Macaca mulatta) - share this developmental achievement. We presented macaques with a looking-time measure of false belief understanding, one that had recently been developed for use with 15-month-old human infants. Like human infants, monkeys look longer when a human experimenter fails to search in the correct location when she has accurate knowledge. In contrast to infants, however, monkeys appear to make no prediction about how a human experimenter will act when she has a false belief. Across three studies, macaques' pattern of results is consistent with the view that monkeys can represent the knowledge and ignorance of others, but not their beliefs. The capacity to represent beliefs may therefore be a unique hallmark of human cognition.     

Robustness of parameter and standard error estimates against ignoring a contextual effect of a subject-level covariate in cluster-randomized trials

In experimental research, it is not uncommon to assign clusters to conditions. When analysing the data of such cluster-randomized trials, a multilevel analysis should be applied in order to take into account the dependency of first-level units (i.e., subjects) within a second-level unit (i.e., a cluster). Moreover, the multilevel analysis can handle covariates on both levels. If a first-level covariate is involved, usually the within-cluster effect of this covariate will be estimated, implicitly assuming the contextual effect to be equal. However, this assumption may be violated. The focus of the present simulation study is the effects of ignoring the inequality of the within-cluster and contextual covariate effects on parameter and standard error estimates of the treatment effect, which is the parameter of main interest in experimental research. We found that ignoring the inequality of the within-cluster and contextual effects does not affect the estimation of the treatment effect or its standard errors. However, estimates of the variance components, as well as standard errors of the constant, were found to be biased.     

Assessing women's responses to sexual threat: validity of a virtual role-play procedure

This study evaluated the validity of a role-play procedure that uses virtual reality technology to assess women's responses to sexual threat. Forty-eight female undergraduate students were randomly assigned to either a standard, face-to-face role-play (RP) or a virtual role-play (VRP) of a sexually coercive situation. A multimethod assessment strategy was used to evaluate the efficacy of the role-play procedure in creating a realistic and immersive situation. Consistent with our hypotheses, women in the VRP condition exhibited greater negative affect and immersion than women in the RP condition. In addition, the level of assertive refusal in the VRP, but not the RP, condition differentiated between women with and without a prior history of sexual victimization. These findings provide evidence of the validity of a virtual role-play procedure for assessing women's responses in sexually threatening situations.     

Bernard Williams on the Human Prejudice

In “The Human Prejudice”, Bernard Williams discusses our treating human beings differently in our moral thinking from the ways we treat other creatures. He criticises the idea that this expresses a prejudice, speciesism, analogous to racism and sexism. His essay has been misunderstood by some of its critics, including Peter Singer and Jeff McMahan. My essay sets out several questions one may have about Williams's essay, and explains how they can be answered. I make clear the connections between “The Human Prejudice” and some main elements in Williams's thinking about ethics, including his criticisms of moral theory.