Next time you find yourself somewhere with lots of tourists, try to guess where they're from based only on their behavior (no eavesdropping). The woman carrying her empty soda bottle for blocks and blocks, rejecting trash cans that are close to overflowing, until she finds one where the bottle won't fall out? Probably one of those superconscientious Swiss. That group flocking to name-brand retailers? Conformist Japanese, perhaps. That man armed with a map and checking off items on his to-see list? A disciplined, goal-oriented German. For the bonus round: if you peg someone as American, which state? Hint: Wisconsin has very extroverted residents, finds an upcoming study, while West Virginians and Rhode Islanders rank highest on neuroticism.
Linking personality to where someone hails from is more than a game, however. About 20 years ago scientists established that combinations of five basic dimensions—extroversion, agreeableness, conscientiousness, neuroticism and openness to new ideas and experiences—account for all personalities. Add a pinch of openness, a dollop of agreeableness and, like Grandma's secret recipe for pasta sauce, the result is unique. The five dimensions can be reliably measured with questionnaires. Armed with the resulting data, scientists are showing that personality predicts such important outcomes as health, job performance and academic success— things that we pretend are matters of conscious control or public policy. In some cases the trait plays a direct causal role, as when a lack of conscientiousness torpedoes workplace success. In others, the connection is indirect, as when being disagreeable leaves you with no social network, which can cause stress and thus poor health. Some connections are just head-scratchers: in the last three presidential elections, states high in openness and low in conscientiousness gave the Democrat a bigger winning margin than did states low in openness and high in conscientiousness, even after controlling for income, education and race.
Since personality is so important to both social and individual outcomes, the hunt is on for which traits vary geographically and why. According to the most extensive study yet of how personality varies across the United States, a "neuroticism belt" divides the East and West, with states from Maine to Louisiana scoring highest and the West lowest, find Jason Rentfrow of Cambridge University and colleagues. There is also a geographic divide in openness (a measure of willingness to embrace new ideas and creativity), with the Northeast and West Coast much higher than the Midwest and South, according to the data from 619,397 people who filled out an online personality survey and were representative of the U.S. population in education, income and other measures. Extroversion is highest in the Great Plains, Midwest and Southeast, and lowest in the Northwest and Northeast, the scientists will report next month in Perspectives on Psychological Science. For agreeable people, go to the Midwest and Southeast, and avoid the Northeast. For conscientiousness, head for the South and Midwest, not the Northeast. At a finer scale, Alaskans may be amused (or not) that they rank dead last in agreeableness and conscientiousness, while North Dakotans rank highest on extroversion and agreeableness but last in openness. The good folks of Utah are the least neurotic.
The Big Five personality traits cluster globally, too. Although specific stereotypes do not hold up—northern Italians are not bureaucratic and cold compared with their passionate southern compatriots, says Robert McCrae of the National Institute on Aging, a pioneer in the geography of personality—the prevalence of different traits varies by region. German Swiss see themselves as super conscientious, as do Swedes and people from Burkina Faso. Turks and Indonesians, not really. Russians and Botswanans rate their compatriots as quite agreeable, while Argentines and Americans bring up the rear. Puerto Ricans and Australians are tops in extroversion; Estonians and Japanese, the world's shrinking violets.
Just as personality shapes an individual, so it does society. Regions high in extroversion have more people in occupations like sales and nursing where social interaction is essential. Their residents are also more socially involved. Conscientiousness goes along with healthy behaviors, and tends to breed more computer scientists, who prefer "systematic and focused tasks and clearly defined rules," says Rentfrow. But there are more artists and entertainers in low-conscientiousness and high-openness places—as well as high patent production.
In a mobile society, the reasons traits cluster may be as simple as people moving to where they'll fit in (open-minded places draw open-minded people) and leaving places they do not. But there is good evidence that the customs and institutions that arise from the dominant personality of a place can shape the personalities of people who are not that way to begin with. "Where new ideas and diversity are valued," says Rentfrow, "it can influence how people there feel and behave, altering their natural dispositions." Such changes might just have as strong an influence as public policies on health, economic strength and other things we value.