Marital conflict and conduct problems in Children of Twins

The Children-of-Twins design was used to test whether associations between marital conflict frequency and conduct problems can be replicated within the children of discordant twin pairs. A sample of 2,051 children (age 14-39 years) of 1,045 twins was used to estimate the genetic and environmental influences on marital conflict and determine whether genetic or environmental selection processes underlie the observed association between marital conflict and conduct problems. Results indicate that genetic and nonshared environmental factors influence the risk of marital conflict. Furthermore, genetic influences mediated the association between marital conflict frequency and conduct problems. These results highlight the need for quasiexperimental designs in investigations of intergenerational associations.     

Effects of a motivational climate inntervention for coaches on young athletes' sport performance anxiety

The mastery approach to coaching is a cognitive-behavioral intervention designed to promote a mastery-involving motivational climate, shown in previous research to be related to lower anxiety in athletes. We tested the effects of this intervention on motivational climate and on changes in male and female athletes'cognitive and somatic performance anxiety over the course of a basketball season. Hierarchical linear modeling analyses revealed that the athletes in the intervention condition perceived their coaches as being more mastery-involving on the Motivational Climate Scale for Youth Sports when compared to athletes in an untreated control condition. Relative to athletes who played for untrained coaches, those who played for the trained coaches exhibited decreases on all subscales of the Sport Anxiety Scale-2 and on total anxiety score from preseason to late season. Control group athletes reported increases in anxiety over the season. The intervention had equally positive effects on boys and girls teams.     

Do physical activity beliefs differ by age and gender?

Age and gender are consistently related to physical activity (PA), yet theoretical explanation for these associations is scant. The present study compared the mean values and correlations of a population sample, divided by gender and age group, with respect to theory of planned behavior beliefs (behavioral, normative, and control) and PA. Participants were a sample (N=6,739) of adults (M age=49.65, SD=16.04) who completed measures of social and health demographics, theory of planned behavior beliefs, and self-reported PA. Mean analyses identified greater perceived control over PA for seniors than for young and middle-aged adults (N>.025). Belief-behavior correlations, however, were not different across age and gender in 24 of 26 tests (q<.19). Thus, PA beliefs are invariant across age and gender with the exception of mean levels of perceived control, which are lower among younger adults than older adults. Factors such as early parenthood and career demands were considered the likely reasons for differences. Overall, the evidence suggests that adapting theoretical models for specific age groups or based on gender may not be necessary.     

Coordination variability and skill development in expert triple jumpers

The aim of this study was to examine the influence of skill of expert triple jumpers on the coordination variability of lower extremity intra-limb couplings. In contrast to the traditional motor learning perspective, we hypothesized that as skill and thus performance increases, movement coordination variability will also increase. Three-dimensional kinematic and ground reaction force data were collected during the hop-step transition phase of the triple jump. Relative motion plots and a modified vector coding technique were used to quantify the coordination variability across the trials. The results were consistent with a U-shaped curve, representing coordination variability, as skill increases. The high coordination variability in less skilled athletes is present while the appropriate characteristics defining the movement coordination patterns are acquired. This coordination variability may not be beneficial to performance. As the refinement of these characteristics is achieved, coordination variability decreases, resulting in a more consistent or regulated performance. In the final stages of developing a skilled performance, a functional variability is accessed that brings flexibility to the system allowing it to cope with perturbations. This study highlights the need to address the learning effect when analysing coordination variability from a dynamical systems perspective.     

Fourth-grade students' motivational changes in an elementary physical education running program

Achievement goal theory and the expectancy-value model of achievement choice were used to examine fourth-grade students' motivational changes in an elementary physical education running program. In fall and spring of the school year, participants (N = 113; 66 boys, 47 girls) completed questionnaires assessing achievement goals, expectancy beliefs, subjective task values, and intention for future running participation. They also completed a timed 1-mile (1.6 km) run. The number of laps they ran/walked during the school year was used to assess students' persistence/effort. Results indicated the students improved their run but became less motivated about running while participating in a year-long running program. Children's beliefs about how good they were in the running program (i.e., expectancy beliefs) and their perceptions of how interesting and fun it was (i.e., interest) emerged as the strongest positive predictors of their motivation for running over time. These findings provide strong empirical evidence that expectancy beliefs and interest are essential to children's motivation in elementary physical education.