Cingulate

The scientists used a group of students in their study. They discovered that students who described themselves as social and economic liberals had a greater density of gray matter in a brain region called the anterior cingulate.

In the study, led by Ryota Kanai of the University College London, people who identified themselves as liberals generally had a larger anterior cingulate cortex — a comma-shaped region near the front of the brain that is involved in decision-making. By contrast, those who identified as conservatives had larger amygdalas — almond-shaped structures that are linked with emotional learning and the processing of fear.