This study was designed to investigate friend influence on academic achievement and task avoidance during middle childhood in a sample of 794 participants in 397 stable same-sex friendship dyads (205 girl dyads and 192 boy dyads) from four municipalities in Finland: two in Central Finland, one in Western Finland, and one in Eastern Finland. Longitudinal data were collected during the spring of 3rd grade and 4th grade and reports were available from both members of each friendship dyad. The Actor-Partner Interdependence Model (APIM; Kenny, Kashy & Cook, 2006) was used with a single sample of participants to estimate friend influence on academic achievement and task avoidance between two types of friendship dyads: (1) dyads that were distinguishable as a function of relative math achievement and relative peer acceptance and (2) dyads that were indistinguishable as a function of relative math achievement and relative peer acceptance. The results demonstrate that when friends are distinguished by math achievement the high achiever influences the low achiever’s math achievement, but not the reverse. When friends are distinguishable by peer acceptance the high accepted partner influences the low accepted partner’s math achievement, but not the reverse. When friends are indistinguishable on the basis of math achievement and peer acceptance there is mutual influence on math achievement. There was no evidence of friend influence on task avoidance. There was no evidence of friend influence from an individual’s own task avoidance predicting changes in friend math achievement, except among dyads that could not be distinguished on the basis of math achievement. Math achievement predicted within-individual changes in task avoidance for all friendship dyads, except those that could not be distinguished by relative math achievement. The findings suggest that friends influence math achievement during middle childhood. Furthermore, when friends are distinguished, relative math achievement and peer acceptance determines who is influencing whom within a friendship dyad. The use of the APIM for distinguishable and indistinguishable dyads on a single sample of participants illustrates that it is not sufficient to ignore differentiating features between friends, or to discard friendships that are more similar. Implications for teaching strategies and classroom interventions are discussed. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2013.

Criminologists have long since documented a connection between peer deviance and personal deviance. Some theories suggest that this connection is due to a learning process where individuals may adopt the attitudes, beliefs, and behaviors of those with whom they have significant interactions, such as friends. While individuals may be susceptible to learning anti-social behavior from peers, it is unclear if certain personality characteristics may affect this relationship. The purpose of this study is to determine if differences in specific personality characteristics, such as self-esteem, introversion and extroversion, can have a moderating effect on the pressures to participate in the use of drugs and alcohol that are projected on to individuals during their adolescent years. The findings of the current study can lead to new pathways in substance use prevention and personality assessment in conjunction with risk assessment for juveniles during their middle and high school years. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2015 / FAU Electronic Theses and Dissertations Collection