A new brain study out of USC looks at why people are so resistant when their political views are challenged by others.

LOS ANGELES — When it comes to politics, it can be difficult to accept the other side. Some friendships have even ended as a result of opposing political views. Last November’s presidential election is a prime example of a politically divided America.

So why do people get emotional and even angry when their political beliefs are challenged? USC professor Jonas Kaplan‘s research suggests that the brain may actually be to blame.

The cognitive neuroscientist started studying how the brain reacts when one’s political beliefs are challenged a few years ago, not realizing how America’s political climate would turn out.

“I don’t think we could have predicted how much these issues would be on everybody’s minds when we finished the study several years later.” Kaplan told CBS Los Angeles.

Kaplan and colleagues at USC’s Brain and Creativity Institute performed functional MRI scans of the brains of 40 participants with strong liberal political views, watching their brain activity as his team presented counter-arguments and tried to sway their political positions.

The MRIs showed that the parts of the brain that were…