Voting behavior is reflected in amygdala response across cultures.

Voting to determine one's leaders is among the most important decisions we make, yet little is known about the brain's role in how we come to these decisions. Behavioral studies have indicated that snap judgments of political candidates' faces can predict election outcomes but that the traits that lead to these judgments differ across cultures. Here we sought to investigate the neural basis for these judgments. American and Japanese natives performed simulated voting judgments of actual American and Japanese political candidates while neural activity was measured using functional magnetic resonance imaging (fMRI). Candidates for whom participants chose to vote elicited stronger responses in the bilateral amygdala than candidates for whom participants chose not to vote. This was true regardless of either the participant's culture or the target's culture, suggesting that these voting decisions provoked the same neural response cross-culturally. In addition, we observed a participant culture by target culture interaction in the bilateral amygdala. American and Japanese participants both showed a stronger response to cultural outgroup faces than they did to cultural in group faces, however this was unrelated to their voting decisions. These data provide insight to the mechanisms that underlie our snap judgments of others when making voting decisions and provide a neural correlate to cross-cultural consensus in social inferences.