Brain scanners can predict your political ideology


Whether you pulled the lever for Barack Obama or Mitt Romney may reflect how your brain deals with risk, new research shows.

The study, which looked at the brain activity of 35 men and 47 women registered as Democrats or Republicans, found no difference in the amount of risk people of each political persuasion were willing to take when playing a game. by chance. But the way the brain handled risk worked differently between groups, with Republicans showing more activity in an area related to reward, fear, and risky decisions and Democrats showing more activity in an area related to treatment. emotions and internal body signals.

The results suggest fundamental differences between people with different values, said researcher Darren Schreiber of the University of Exeter.

“The ability to accurately predict party politics using only brain activity during play suggests that studying basic neural differences between voters may provide us with more powerful information than traditional political science tools.” Schreiber said in a statement. [The 10 Greatest Mysteries of the Mind]

The risk policy

Recent surveys of the psychology of liberals and conservatives have found a number of subtle differences, from conservatives showing more disgust to liberals paying less attention to negative stimuli or threats.

A 2011 study published in the journal Current Biology found differences in certain brain structures between politically liberal and politically conservative young adults. Many of these areas were related to risk assessment and decision-making, which prompted Schreiber and his colleagues to wonder if they could find any differences in the way these areas operate during risky tasks.

The researchers had previously conducted a study in which people had brain scans while playing a game of chance. On each round, participants saw three digits, 20, 40 and 80, flashing on a screen. If they hit a button while 20 was up, they were guaranteed 20 cents. If they waited for the 40 or the 80, they might get a payout of 40 or 80 cents – but they could also lose that amount of money. Thus, they chose between a safe bet and two more profitable but riskier options.

Using voting records, the researchers uncovered the political party affiliation of 35 of the men and 47 of the women in this study. Political parties do not fit ideology perfectly, but they are very close, the researchers wrote on February 13 in the journal PLOS ONE. Most Democrats have liberal values, while most Republicans have conservative values.

Political brains

Comparison of Democratic and Republican participants revealed differences in two regions of the brain: the right amygdala and the left posterior insula. Republicans showed more activity than Democrats in the right amygdala when they made a risky decision. This region of the brain is important for processing fear, risk, and reward.

Meanwhile, Democrats have shown more activity in the left posterior insula, a part of the brain responsible for processing emotions, especially visceral emotional signals from the body. The particular region of the insula that showed increased activity has also been linked to “theory of mind,” or the ability to understand what other people might be thinking.

While their brain activity differed, the behaviors of the two groups were identical, according to the study.

Schreiber and his colleagues cannot say whether functional differences in the brain push people towards a particular ideology or not. The brain changes depending on how it is used, so it’s possible that acting in a partisan way makes for differences.

Functional differences dovetailed well with political beliefs, however. Researchers were able to predict a person’s political party by examining their brain function 82.9% of the time. In comparison, knowing the structure of these regions can correctly predict the party 71% of the time, and knowing the political affiliation of someone’s parents can tell you theirs 69.5% of the time, the researchers wrote.

Follow Stéphanie Pappas on Twitter @sipappas or LiveScience @sciencelive. We are also on Facebook & Google+.


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