Map of 3 million personality tests showing regional neuroticism (fear) and voting behavior in the United States. Credit: Social Psychological and Personality Science

Regions where voters have more neurotic personality traits were more likely to vote for Donald Trump in the United States or for the Brexit campaign in the United Kingdom, revealing a new trend that could help explain the rise of fearmongering populist political campaigns across the world, according to new research published in the journal Social Psychological and Personality Science.

Researchers analyzed personality traits from online surveys of more than 3 million people in the United States and more than 417,000 people in the United Kingdom. Election data was compiled from public sources.

"Our study reveals how neuroticism or psychological hardship is shaping the global political landscape," said lead study author Martin Obschonka, PhD, a psychologist and associate professor at Queensland University of Technology in Australia. "One could also call this 'irrational' voting behavior because the surprising success of Trump and Brexit weren't predicted by models that relied on a rational understanding of voters."

Neuroticism hasn't previously been associated with voting behavior, suggesting that it could have been a "sleeper effect" with the potential to have a profound impact on the success of populist political campaigns across the globe, Obschonka said.

The Trump and Brexit campaigns both promoted themes of fear and lost pride, which are related to neurotic personality traits that include persistent feelings of fear, anxiety, depression, envy or jealousy. Regions in the United States with greater support for Trump were very similar to areas in the United Kingdom that supported Brexit, including a higher percentage of white people and lower levels of college education, earnings and liberal attitudes. Former industrial areas that are now in economic decline also were more likely to support Trump or Brexit.

Maps of UK voting patterns and personality test results in 2016. Credit: Social Psychological and Personality Science

The Brexit vote in June 2016 by the United Kingdom to leave the European Union succeeded by a very narrow margin, with 51.9 percent of voters in favor. Trump's presidential victory in 2016 also shocked many people, with him winning 30 states and the electoral vote tally even though 2.8 million more Americans voted for Hilary Clinton.

Trump's crucial voter gains above the performance of 2012 Republican presidential candidate Mitt Romney occurred largely in areas with high levels of neurotic traits, including battleground states such as Pennsylvania, Wisconsin, and Ohio, which shifted from Democratic in 2012 to Republican in 2016. Trump's populist campaign also was especially successful in former industrial centers that are now in economic decline, including the Rust Belt region across the Midwest and Great Lakes.

The researchers examined regions, not individuals, and were studying larger trends relating to psychological traits, not specific diagnoses of mental illness for any voters. The study also excluded Northern Ireland from the Brexit analysis because of the lack of available data.

The fears and worries of voters with neurotic personality traits should be taken seriously, and facts should be provided during political campaigns to allay those fears, Obschonka said. Education also could be a buffer against fearmongering populist political campaigns because regions with higher rates of college graduates had much lower levels of neuroticism, he said.

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More information: Martin Obschonka et al, Fear, Populism, and the Geopolitical Landscape, Social Psychological and Personality Science (2018). Journal information: Social Psychological and Personality Science Martin Obschonka et al, Fear, Populism, and the Geopolitical Landscape,(2018). dx.doi.org/10.1177/1948550618755874