Friendship relations in terms of interpersonal influence, self-disclosure and extent of social activities were studied among impulsive and non-impulsive university students. The procedure involved having impulsive and non-impulsive subjects bring a friend into the laboratory. Questionnaire and autokinetic studies of mutual influence revealed that impulsive subjects were less influenced by friends' judgements and dominated their good friends more than non-impulsive subjects. Impulsive subjects also socialized more with their good friends and disclosed more intimate information about themselves than non-impulsive subjects. In a second study it was found that the judgements of a male stranger had no influence upon impulsive subjects judgements, while a female stranger did influence their judgements. Both male and female strangers influenced the judgements of non-impulsive subjects. Other findings were that friends resembled subjects in terms of impulsivity test scores. The findings are discussed in terms of the functional value of friendship for persons varying in impulsivity.