Stiffness as a control variable in motor performance

In the experiments described in this article we investigated the control of stiffness of the effector system in relation to parameters of the movement. If the velocity of a movement is chosen, it appears that at the same time the stiffness of the effector system is set to a preferred value. By changing the instruction given to the subject it is possible to change the relationship between velocity and stiffness without changing the kinematic parameters of the movement.Finally, the changes of stiffness and velocity in a learning process are studied. In conformity with what might be expected on intuitive grounds, it is found that velocity increases spontaneously during learning while stiffness decreases. The results are discussed in connection with the generation of motor programmes.     

An evaluation of the Tripartite Influence Model of body dissatisfaction and eating disturbance with adolescent girls

The Tripartite Influence Model of body image and eating disturbance proposes that three formative influences (peer, parents, and media) affect body image and eating problems through two mediational mechanisms: internalization of the thin-ideal and appearance comparison processes. The current study evaluated this model in a sample of 325 sixth through eighth grade girls. Simple path analyses indicated that internalization and comparison fully mediated the relationship between parental influence and body dissatisfaction and partially mediated the relationship between peer influence and body dissatisfaction. Additionally, internalization and comparison partially mediated the relationship between media influence and body dissatisfaction. Six a priori SEM models based on the full Tripartite Influence Model were also evaluated. A resulting model was found to be an adequate fit to the data, supporting the viability of the Tripartite Model as a useful framework for understanding processes that may predispose young women to develop body image disturbances and eating dysfunction.     

Creativity and Imitation: Effects of Regulatory Focus and Creative Exemplar Quality

In creative settings, exposure to creative exemplar products may invite imitation and as such influence creative performance. In understanding creativity, it, therefore, is important to be able to predict imitation of creative exemplar products. Regulatory focus theory can do so, and leads to predictions that deviate from the existing body of knowledge concerning regulatory focus and creativity in the absence of exemplar products. In this study, we proposed that high creative exemplar quality elicits more imitation—and thus lowered creativity—for promotion-focused individuals, whereas creative exemplar quality does not affect the creative process for prevention-focused individuals. To enable a relatively objective measurement of creativity and imitation, these predictions were tested in a laboratory experiment. Results supported predictions, indicating that knowledge about how strongly people engage in imitation in the face of a creative exemplar product leads to more adequate predictions how creative people really are.     

Investigating metrical and structural aspects of visual completion: Priming versus searching

Earlier research on visual occlusion showed some flexibility in the formation of visual completions, as long as the structural aspects (e.g., symmetry) of the visible part of the partly occluded shape were preserved in the completion (de Wit & van Lier, ). In this study, we examined whether changing the overall size of the occluded shape would preserve the overall structure. In Experiment 1, using the primed‐matching paradigm, we found evidence for relative size invariance in the completion process. To investigate whether changes in the structural aspects of shape are generally more salient than those of size, we employed the same stimuli in visual search and change detection paradigms. Experiment 2 demonstrated effects of completion in both paradigms. Experiment 3 showed that the metrical aspects of the shapes used in Experiment 1 are nevertheless detected faster than the structural aspects under search conditions. Because the variation in structural aspects is not more salient than in metrical aspects, we conclude that for these shapes, visual completion is indeed size‐invariant. The relations between performances in the three paradigms are discussed.     

Follower need for cognitive closure as moderator of the effectiveness of leader procedural fairness

Leader procedural fairness is an important factor in leadership effectiveness, but the study of the contingencies of its influence is still in its infancy. Addressing this issue we focus on the moderating role of follower need for cognitive closure, the disposition to reduce uncertainty and swiftly reach closure in judgement and decision. We propose that need for closure captures followers sensitivity to the uncertainty-reducing influence of leader procedural fairness. Across three studies designed to yield complementary evidence (two surveys and a scenario experiment), we find support for the hypothesis that perceived leader procedural fairness has a stronger (positive) relationship with leadership effectiveness for followers higher in need for closure. This support is found across a variety of indicators reflecting different aspects of leadership effectiveness: effort and performance, social identification, job satisfaction, and leader evaluations. We discuss how these findings advance our understanding of the uncertainty-reducing role of leader fairness.     

Habit as moderator of the intention–physical activity relationship in older adults: a longitudinal study

This longitudinal study examined whether habit strength moderates the intention–physical activity (PA) relationship in older adults, within the framework of the attitude–social influences–efficacy (ASE) model and the theory of planned behaviour (TPB). A total of 1836 older adults (M _age?=?62.95?years, SD _age?=?8.17) completed a questionnaire on social cognitive constructs and PA habit strength at baseline, and six?months later a measure of PA. Three PA habit groups (i.e. low, medium and high) were composed, based on tertiles of the mean index score. Multi-group structural equation modelling analyses showed that intention significantly determined PA behaviour only in participants with a low or medium habit strength towards PA. This result suggests that PA is not intentional at high levels of habit strength and demonstrates the usefulness of incorporating habit in the ASE and TPB models. Results also showed that about half of the participants with a strong PA habit did not meet the recommended PA level. As strong habits may prevent intentional behavioural change and may hinder the receptiveness and openness for informational PA change strategies, additional intervention strategies, such as awareness raising and the use of implementation intentions, are needed for strongly habitual, but insufficiently active older adults.     

Effects of Spatial and Motor Demands in Handwriting

Four experiments were conducted to study response programming in handwriting tasks. Twelve right-handed subjects wrote acoustically presented words and phrases, and their handwriting was digitally recorded. Changes in latency, movement time, trajectory length, and pen pressure were studied as a function of response complexity (i.e., word length, complexity of initial letter, and spacing distance). The lengthening of the spatiotemporal parameters preceding the more complex structures is interpreted to be a reflection of the effects of mental load. The results further indicate that the choice of a programming strategy is dependent on the structural complexity of the task. Writing pressure decreased as a function of increased sequence length. The findings support a hierarchical model of handwriting.     

Social Identity and Personal Identity Stereotype Threat: The Case of Affirmative Action

Integrating insights from research examining the effect of being seen through the lens of stereotypes on academic performance and the social identity perspective, we examine the effect of perceived affirmative action admission at college entry on academic performance at the end of the first year. We propose that stereotype threat plays a crucial moderating role in determining when performance is affected. A longitudinal study of Black and Latino students at a large multiethnic university showed that perceptions of affirmative action admission negatively affected achievement among high stereotype-threatened individuals but not among low stereotype-threatened individuals. Furthermore, the results show that stereotype threat can have its effects because of concerns for the self (personal identity stereotype threat) or because of concerns for the group (social identity stereotype threat). As expected, social identity stereotype threat negatively affected the performance of individuals high in ethnic identification, whereas personal identity stereotype threat negatively affected the performance of individuals low in ethnic identification.     

Acculturation and Cognitive Performance of Migrant Children in The Netherlands

Acculturative strategies and cognitive acculturation were studied among 118 Dutch migrant children (age: 7–12 years). Both an exploratory factor analysis and a Linear Logistic Test Model analysis provided evidence for the bipolar unidimensionality of Berry's four acculturation strategies; integration constituted one pole and assimilation, separation, and marginalization the other. Integration was by far the most popular strategy. Cognitive performance was measured by the Snijders-Oomen Nonverbal Intelligence Test, school report measures, and a computer-assisted choice reaction-time measure. A good fit was found for a structural model that postulated cognitive acculturation as the latent variable linking background measures (i.e. acculturation strategy, second language usage, age, and gender) to the cognitive measures. Relationships between background variables and cognitive performance were stronger in the first than in the second generation. Both older children and children who favour an integration strategy showed a higher degree of cognitive acculturation.