In the United States, the meaning of the term has changed dramatically over the last 60 years. Before the American National Election Study (described in Angus Campbell et al., in "The American Voter") began in 1952, an individual's partisan tendencies were typically determined from their voting behavior. Since then, "partisan" has come to refer to an individual with a psychological identification with one or the other of the major parties. Candidates, depending on their political beliefs, may choose to join a party. As they build the framework for career advancement, parties are more often than not the preferred choice for candidates. Wherein there are many parties in a system, candidates often join them as opposed to standing as an Independent, if that is provided for.