Why voters turn out on Election Day has eluded a straightforward explanation. Rational choice theorists have proposed a parsimonious model, but its logical implication is that hardly anyone would vote since their one vote is unlikely to determine the election outcome. Attempts to save the rational choice model incorporate factors like the expressive benefits of voting, yet these modifications seem to be at odds with core assumptions of rational choice theory. Still, some people do weigh the expected costs and benefits of voting and take account of the closeness of the election when deciding whether or not to vote. Many more, though, vote out of a sense of civic duty. In contrast to the calculus of voting model, the civic voluntarism model focuses on the role of resources, political engagement, and to a lesser extent, recruitment in encouraging people to vote. It pays particular attention to the sources of these factors and traces complex paths among them.
There are many other theories of why people vote in elections. Intergenerational transmission and education play central roles in the civic voluntarism models. Studies that link official voting records with census data provide persuasive evidence of the influence of parental turnout. Education is one of the best individual-level predictors of voter turnout, but critics charge that it is simply a proxy for pre-adult experiences within the home. Studies using equally sophisticated designs that mimic the logic of controlled experiments have reached contradictory conclusions about the association between education and turnout. Some of the most innovative work on voter turnout is exploring the role of genetic influences and personality traits, both of which have an element of heritability. This work is in its infancy, but it is likely that many genes shape the predisposition to vote and that they interact in complex ways with environmental influences. Few clear patterns have emerged in the association between personality and turnout. Finally, scholars are beginning to recognize the importance of exploring the connection between health and turnout.