One state's citizens are collectively more agreeable and another's are more conscientious. Could that influence how each state is governed?
A recently published study suggests it could.
Jeffery Mondak and Damarys Canache, political science professors at the University of Illinois, analyzed personality data from more than 600,000 Americans, identified by state, who had responded to an online survey for another research study. They then matched that data with state-level measures of political culture, as identified by other, unrelated research.
The results were striking. "Variation in personality across the American states corresponds quite strongly with states' core political characteristics," they write in a paper published in the March issue of the journal Political Research Quarterly.
The study does not prove a cause and effect, only a correlation between collective personality traits and political culture within states, says Mondak, the James M. Benson Chair in Public Issues and Civic Leadership, who has been studying the intersection between psychology and politics for nearly two decades. (His 2010 book, "Personality and the Foundations of Political Behavior," was one of the first on the subject.)
Establishing the connection is significant, however, Mondak said. "It's important that we figure out what makes individuals tick and then how that connects to what makes societies tick," he said. "Now we know that these individual-level psychological properties are related - and strongly related - to key aspects of political culture that have been studied for decades."
Mondak's study of personality and politics is based on the "five factor" or "Big Five" model that has revolutionized the study of personality since the late 1980s, he said. The model provides a structure for grouping hundreds of personality traits under five broad dimensions: openness to experience, conscientiousness, extroversion, agreeableness (friendly vs. more distant) and neuroticism (or its reverse, emotional stability).
In fact, many personality tests that have become popular online - such as those offering to tell you which U.S. president or "Seinfeld" character you're most like - are based on the "Big Five," Mondak said.
All of the five dimensions are on a continuum and the model is not designed to make judgments about certain traits or suggest any ideal personality, he said. Being open to experience, for instance, can make someone more open to both good and bad, and healthy and unhealthy, behaviors.
Among the researchers' findings was that states with lower levels of conscientiousness or higher levels of agreeableness were very likely to have a political culture that saw government as a positive force committed to the collective good. States lower in agreeableness were very likely to have a political culture focused on individualism and smaller government.
Also, states that were higher in openness to experience had citizenries that tended to be ideologically liberal. Massachusetts, New York and Oregon are all good examples of that, Mondak said, since they all were among the highest in both categories.
States with higher levels of conscientiousness, on the other hand, were very likely to have a political culture more committed to maintaining traditional social hierarchies, and to have populations that were more ideologically conservative. Mississippi, South Carolina and Tennessee all are good examples.
The researchers also found links between personality traits and other criteria related to political and civic culture. States that collectively showed more openness to experience, for example, had higher rates of women in state legislatures and home Internet access. Those high in conscientiousness had higher rates of violent crime, as well as lower rates of home Internet access.
These links between personality and politics are all the more interesting because the difference in collective personality between states is small, Mondak said. "Individuals vary a lot in their personalities. States don't vary a lot. We're talking about just a few percentage points," he said.
It's not that surprising, however, Mondak said, when you consider that a small swing of voters in closely contested states can result in dramatically different policies.
The personality data Mondak and Canache analyzed for their study were collected online between 1999 and 2005 for a study led by Peter J. Rentfrow at the University of Cambridge.