Maybe it’ll be something to do with the size of your anterior cingulate cortex:

“Previously, some psychological traits were known to be predictive of an individual’s political orientation,” said Ryota Kanai of the University College London. “Our study now links such personality traits with specific brain structure.”

Kanai said his study was prompted by reports from others showing greater anterior cingulate cortex response to conflicting information among liberals. “That was the first neuroscientific evidence for biological differences between liberals and conservatives,” he explained.

There had also been many prior psychological reports showing that conservatives are more sensitive to threat or anxiety in the face of uncertainty, while liberals tend to be more open to new experiences. Kanai’s team suspected that such fundamental differences in personality might show up in the brain”