On each trial of the primary task for the study, a pair of small circles appeared on a computer screen. Across trials, the circles appeared in an array of positions on the screen. The participant was required on each trial to indicate whether or not the test circles were two or fewer position units apart in terms of the horizontal dimension of this array. The discrimination that the task requir...

In achievement contexts such as sport, achievement goal theory assumes that an individual's major concern is to demonstrate competence. However, competence may be expressed in two ways: as task and ego involvement (Nicholls, 1989). Seventy-eight boys (M age = 13.6 years) performed five climbing courses, and the influence of achievement goals, perceived ability, and task difficulty on effort and...

This article examines how friends' involvement in crime influences such involvement in those around them, as offenders or victims, and the extent to which such friendship effects vary with contact frequency, friendship intimacy, and geographical proximity. To test our hypotheses we used four waves from the Dutch panel survey CrimeNL, which includes ego-centered network measures in each wave for...

This paper summarizes research performed to evaluate the impact of handrail profile dimensions on graspability. It reports on research performed to determine the forces that stairway users exert on handrails when they fall, tests demonstrating the forces persons with various hand sizes can exert on handrails with different profiles, and comparisons of the probability of loss of grip by stairway...

Our interest in vortices arises for two reasons. Firstly, at moderate to large Reynolds numbers (at least 100) which characterise flow in larger arteries, vortices are quite persistent. The presence of vortices in a flow may exert a strong influence on its behaviour, although tracking vortices may be difficult as they can evolve rapidly. The effects of vortices or vortical structures are partic...

Aging populations now exert influence on all aspects of social life. This article examines changes to major social and economic institutions linked with old age, taking the period from the mid-20th century to the opening decades of the 21st century. These developments are set within the context of the influence of globalization as well as the impact of the 2008 financial crisis, these restructu...

Impacts of human land use pose an increasing threat to global biodiversity. Resource managers must respond rapidly to this threat by assessing existing natural areas and prioritizing conservation actions across multiple spatial scales. Plant species richness is a useful measure of biodiversity but typically can only be evaluated on small portions of a given landscape. Modeling relationships bet...

We used a visual illusion called motion repulsion as a model system for investigating competition between two mental representations. Subjects were asked to remember two random-dot-motion displays presented in sequence and then to report the motion directions for each. Remembered motion directions were shifted away from the actual motion directions, an effect similar to the motion repulsion obs...

AIM The purpose of the present study was to investigate the characteristics and effects of motivational music in British gymnasia. The secondary purpose was to determine whether the characteristics and effects of motivational music were invariant in relation to gender, age, frequency of gymnasium attendance, and the time of day at which exercise participants attended gymnasia. METHODS Partici...

We present findings from a field experiment on team diversity. Individuals working as canvassers in an elections-related experiment were randomly assigned a junior teammate, a senior manager and a set of households to visit. This created random variation in the degree of horizontal diversity, vertical (or hierarchical) diversity and external (or client) diversity within each team. We find that ...