The study examined the sensitivity to change of field assessments of handgrip strength and vertical jump following programmatic interventions in physical education settings. Using a naturalistic experimental design, classes of 6th grade students (N = 158) were randomized to receive either an 8-week musculoskeletal strength or plyometric power…

Guided by the life course perspective, this study investigated the developmental antecedents of contact, closeness/warmth, and negativity in young adults' relationships with their parents. Taking the developmental systems approach, we considered interindividual differences in not only initial levels of parenting quality in early adolescence (Grade…

Few longitudinal studies examine how "changes" in parent-child relationships are associated with changes in youth internalizing problems. In this longitudinal study, we investigated how developmental trends (linear change) and year-to-year lability (within-person fluctuations) in parental warmth and hostility across Grades 6 to 8 predict…

Antisocial peer behavior and low parental knowledge of adolescents' activities are key interpersonal risk factors for adolescent substance use. However, how the magnitude of associations between these risk factors and substance use may vary across adolescence remains less well understood. The present study examined the age-varying associations of…

This study examines developmental change across adolescence in the similarity of friends versus nonfriends. This differential in similarity is a key aspect of the organization of the peer context of development: The stronger the correlation between friends for an attribute, the more the attribute delineates clustering and divisions of friendships.…

According to family systems and life course theories, periods of intense change, such as early adolescence, can disrupt stable family systems, leading to changes in family relationships. In this longitudinal study, we investigate 2 types of change in parental hostility and warmth toward their children during early adolescence (Grades 6 to…

Educators seek to develop students' mathematical knowledge retention to increase student efficacy in follow-on classwork, improvement of test scores, attainment of standards, and preparation for careers. Interactive visuals, feedback during problem solving, and incorporation of higher-order thinking skills are known to increase retention, but a…

High-achieving students in economically disadvantaged, rural schools lack access to advanced coursework necessary to pursue science, technology, engineering, and mathematics (STEM) educational and employment goals at the highest levels, contributing to the excellence gap. Out-of-school STEM programming offers one pathway to students' talent…

The purpose of the study was to examine the effectiveness of a Science Technology and Society (STS) approach in terms of student understanding of major processes of science. Participants included twelve teachers who agreed to participate in an experimental study where Science, Technology, and Society (STS) strategies were utilized with one class…

The present study uses an ecological systems perspective to examine how parental involvement in school-related activities in sixth grade influences early adolescents' school bonding and academic achievement in eighth grade. Results of multilevel models of multiple data sources (i.e., adolescents, parents, and principals) suggested that parents'…

Science inquiry has been found to be effective with students from diverse backgrounds and varied academic abilities. This study compared student learning, enjoyment, motivation, perceived understanding, and creativity during a science unit on Models and Designs for 38 sixth grade students (20 male, 18 female; 1 Black, 1 Hispanic and 36 White). The…

Mass media have numerous effects on children, ranging from influencing school performance to increased or reduced aggression. What we do not know, however, is how media availability in the bedroom moderates these effects. Although several researchers have suggested that bedroom media may influence outcomes by displacing other activities (the…

We tested 2 hypotheses derived from Moffitt's (1993) taxonomic theory of antisocial behavior, both of which are central to her explanation for the rise in delinquency during adolescence. We tested whether persistently delinquent individuals become more accepted by their peers during adolescence and whether individuals who abstain from delinquent…

Prospective longitudinal data from over 14,000 youth residing in 28 communities in the rural United States were analyzed to examine the emergence of mixed-sex friendship groups in early adolescence. Youth were surveyed on 5 occasions between fall of 6th grade and spring of 9th grade. At each assessment, youth reported the names of up to 7…

This longitudinal study investigates whether rural adolescents who transition to a new school in sixth grade have higher levels of risky behavior than adolescents who transition in seventh grade. Our findings indicate that later school transitions had little effect on problem behavior between sixth and ninth grades. Cross-sectional analyses found…