Negative political messages exert the greatest neural impact on voters, brain scan study suggests

New neuroimaging research indicates that information about political corruption has a greater impact that positive messages. The study has been published in the journal Political Psychology.

“Two reasons brought us to this research: first, there were no neuroimaging studies that explored the neural processing of corruption and, second, corruption in Spain is not having the expected political consequences (voting behavior), even though everyday citizens watch news about corruption,” said study author Luis-Alberto Casado-Aranda, an associate professor at Madrid Open University.

The researchers recruited 20 people who indicated they were supporters of either the left-wing Spanish Socialist Workers’ Party or the right-wing People’s Party.

“Only participants with high levels of sympathy (8-9, in a scale from 1 to 10) towards conservative and liberal parties were assessed. This aligns with our aim of evaluating what happens in their brain when exposed to news strongly harmful or beneficial for their parties,” Casado-Aranda explained.

While the researchers monitored their brain activity, the participants were shown positive political messages or statements about political corruption that were randomly paired with the logo of either party. For example, some participants read the corruption statement “Fraud and documentary falsification” and were shown the logo of the Spanish Socialist Workers’ Party. The participants then indicated how much the information made them want to support or punish the party.

The researchers found that participants displayed a higher level of punishment for corruption messages related to their rival party. This bias, however, was less noticeable among left-wing supporters.

The brain scan results suggested that messages about corruption (as opposed to the more positive messages) exerted the greatest cerebral impact on all of the participants.

Statements about political corruption were associated with stronger activation of the anterior insula, dorsomedial prefrontal cortex, amygdala, orbitofrontal cortex, thalamus, precuneus, middle frontal gyrus, and inferior parietal gyrus. These brain regions are associated with the processing of punishment, risk, disappointment, and rejection.

Positive political messages, on the other hand, were associated with activation of the anterior cingulate cortex.

Together, the findings indicate “that negative (vs. positive) political messages exert the greatest neural impact on the electorate, and it seems to suggest that conservative sympathizers can experience a more intense partisan bias when exposed to political messages than their opposing counterparts,” the researchers wrote in their study.

“A drawback to this study is that it only measures self-reported punishment and support, and not real voting behavior. Future research should link neural responses during the processing of political messages to actual political affiliation change. Further studies in political psychology should also apply fMRI in different contexts (e.g., countries.),” Casado-Aranda said.

The study, “Does Partisan Bias Modulate Neural Processing of Political Information? An Analysis of the Neural Correlates of Corruption and Positive Messages“, was authored by Luis‐Alberto Casado‐Aranda, Vinod Venkatraman, Juan Sánchez‐Fernández, and Teodoro Luque‐Martínez.