| Adolescent friends are similar in many respects: academic achievement (Altermatt & Pomeranz, 2003; Hamm, 2000), delinquency (Scholte, 1998; Simons, Wu, Conger & Lorenz, 1994; Vitaro, Tremblay, Kerr, Pagani & Bukowski, 1997), smoking and alcohol use (Engels, Knibbe, Drop & De Haan, 1997; Urberg, Degirmencioglu & Tolson, 1998) and pro-active aggression (Poulin & Boivin, 2000). In this project we will raise 4 questions: 1. Friends can be similar on various dimensions: which dimensions are the most important similarity dimensions? 2. Why are similarity dimensions important and how does this importance change during friendships? 3. Are friends alike because they select or influence each other? 4. Do core personality characteristics of adolescents and their friends predict continuation or discontinuation of friendships? |