This thesis tests the prevailing theory in political behavior that Millennial citizens in the United States substitute alternative political behaviors for voting in order to fill their need for civic engagement. Using 2011 Youth and Participatory Politics Survey Project Wave 1 data [n=2920] of people in America aged 15-25, analysis of youth behaviors and attitudes is conducted via Logistic Regression and Ordinal Logistic Regression. Among older respondents, findings are surprising: most concepts tested are either neutral, in the case of boycotts, protests, online groups, and web-based petitions, or demonstrate relationships in the opposite of the direction theory suggests, in the case of paper petition signing and social media activism. Only a catch-all `other event' behaves as expected based on the theory and is significantly negative. Among younger respondents, online political groups are positively associated with likelihood of voting, but no other results are significant. This provides support for the idea that formal and informal political behaviors, at least among the younger members of the Millennial Generation, are more likely to occur together than to substitute for one another. Additionally, a confirmatory factor analysis is conducted to determine how valid the formal-informal divide among political behaviors is, with mixed and inconclusive results that suggest the concept needs further development.