Graduation Year


Document Type




Degree Name

Master of Arts (M.A.)



Degree Granting Department


Major Professor

Marina Bornovalova, Ph.D.

Committee Member

Mark Goldman, Ph.D.

Committee Member

Geoffrey Potts, Ph.D.


gene-environment interaction, gene-environment correlation, dopamine, electroencephalogram


Risk-taking behavior (RTB) is defined as behavior involving the probability of reward with concurrent probability of some negative outcome. Peer influence is among the most robust predictors of RTB, such that greater peer influence, particularly deviant or delinquent peer influence, is associated with increased RTB. Evidence suggests that those with genetic predispositions for RTB may also be more susceptible to peer influence as a function of genotype. Given that genetic polymorphisms within the dopaminergic system have evidenced associations with various forms of RTB and delinquent peer affiliation, it is possible that these genes may interact with peer influence to predict increased RTB, a process called gene × environment interaction (G×E). We expected that those genetically at risk would take more risks in the presence of a peer than alone. To test this effect, five polymorphisms within the dopaminergic system were genotyped in a sample of 85 undergraduate students. Participants completed a behavioral risk task alone and in the presence of a peer providing "risky" feedback. No significant G×Es were identified for any of the dependent variables. However, participants took significantly more risks in the presence of a risky peer than when taking risks alone. These results suggest that G×E may not be a relevant process for peer-influenced RTB during late adolescence. It is possible that G×E is a relevant process during early adolescence, while gene-environment correlation (rGE) is the dominant process during late adolescence. Future research would benefit from testing whether these genes are relevant to G×E in early adolescence, as well as to rGE during late adolescence.