Wlaschin, Jhon2011-10-112011-10-112011-08https://hdl.handle.net/11299/116557University of Minnesota Ph.D. dissertation. August 2011. Major: Psychology. Advisors: Alexander J. Rothman, Jeffry A. Simpson. 1 computer file (PDF); vii, 191 pages, appendices A-J.The transition to college is an especially vulnerable time for young adults to gain weight. Peers are likely to be a source of influence when young adults begin to form habits concerning their eating and physical activity. This study examined social influences on weight related behaviors using dyadic growth curve analysis of data from 95 young adult roommates assessed 3 times during their freshman year of college. Initial after dinner snacking behavior was highly concordant when roommates first met but became less concordant as the semester progressed suggesting an impression management effect. Perceptions of partner's diet and exercise values predicted actor's change in after dinner snacking behavior controlling for the perceived norms of friends and other students on campus. This was also true for breakfast skipping indicating a significant effect of interpersonal socialization. Further, roommates tended to directly influence each other's sedentary behavior. TV watching and computer use became more concordant over time particularly for females and roommates who developed close relationships. Amount of actor exercise at baseline also predicted changes in partner's sedentary behavior over 10 weeks of living together. These effects were moderated by gender and relationship quality such that women were more likely to be motivated by impression management concerns and roommates with closer relationships were more likely to mutually influence each other through socialization. The results are some of the first to demonstrate social influence of eating behavior among young adult peers in real world settings without the confound of selection bias.en-USBreakfast SkippingCollege FreshmanDyadsPeer InfluenceSedentary BehaviorSnackingPsychologyThesis or Dissertation