Adolescents may be influenced both by their friends' behaviors and by
the features of their friendships. To examine both types of influence,
seventh and eighth graders (N = 297) were asked in the fall of a scho
ol year to report their involvement and disruption at school. The stud
ents also described the positive and negative features of their best f
riendships. Teachers reported on the students' involvement, disruption
, and grades. These assessments were repeated in the following spring.
Students whose friends in the fall described themselves as more disru
ptive increased in self-reported disruption during the year. Girls' se
lf-reported disruption was more influenced by that of their very best
friend than was boys'. Students whose very best friendships had more p
ositive features increased in their self-reported involvement during t
he year. Students whose friendships had more negative features increas
ed in their self-reported disruption, but only if their friendships al
so had many positive features. The theoretical and practical implicati
ons of these findings, and the adequacy of different methods for estim
ating friends' influence, were discussed.