Many psychologists study voting not for its own sake but in order to elucidate more general principles of cognition and social interaction.

For example, Joachim Krueger, PhD, of Brown University, used voting to examine the phenomenon of social projection--the idea that people exaggerate the similarity between themselves and others, particularly members of their own "group." In a 2004 study in Political Psychology (Vol. 25, No. 1), Krueger found that part of the reason voters believe that their behavior matters is that they project their own decision to vote or not vote onto other members of their group--supporters of the same candidate or party.

"If you ask someone whether their one vote will swing the election, most people will rationally say no," Krueger explains. "But because you feel that your decision to vote or abstain is linked to the decisions of many others who feel like you do, you do believe your candidate is more likely to win the election if you vote."

Another example comes from Bibb Latane, PhD, who developed the theory of diffusion of responsibility--the idea that the likelihood that a person will intervene in an emergency or work hard decreases as the number of people available to do that task increases. In a 1998 study, he and a colleague supported that theory by examining 23 New England towns' voting and town meeting records. He found that participation in local town elections and town meetings decreased as the size of the towns increased.

Studies like these show the utility of voting as an example of social behavior, psychologists note. In general, says Stanford University social and political psychologist Jon Krosnick, PhD, voting behavior "is really a question about the relation between individuals and the collectives to which they belong, and social psychology has always been fascinated with that issue."