Adult collaborative cognition research suggests that working with a partner is generally beneficial to performance; however, little research has investigated the relation between the interactive behaviors and collaborative outcome. The present study examined four interactive behaviors exhibited by familiar (i.e., married spouses) and unfamiliar (i.e., other-sex strangers) older adult dyads during collaborative performance on an everyday problem-solving measure. Results indicated that (a) interactive behaviors were related to partner familiarity and whether dyads first attempted the problems individually or collaboratively, (b) the nature of the interactive behaviors differed over the course of task completion, and (c) interactive behaviors were linked to performance outcome. (Contains 4 figures and 3 tables.)