It's no secret that people tend to be unwilling to change their political views, but new scientific research may help us understand what's behind that stubbornness.

A new study published in the journal Scientific Reports, titled "Hard-wired: The brain's circuitry for political belief," found the brain has a defense mechanism that kicks in when your political views are challenged.

As Vox's Brian Resnick explains, it turns out that the brain links your political views with your identity, and just like the brain steps in to defend the body when it senses danger, it kicks in to protect your identity when it senses it's at risk.

Your brain defends your ideals like it's defending your body

“The brain’s primary responsibility is to take care of the body, to protect the body,” Jonas Kaplan, a psychologist at the University of Southern California and researcher for the study, told Vox. “The psychological self is the brain’s extension of that. When our self feels attacked, our [brain is] going to bring to bear the same defenses that it has for protecting the body.”

The researchers put 40 people who identify as liberal in an MRI scanner and presented them with statements likely to challenge their political views. Participants would be shown political statements they might find controversial or contrary to their opinions, as well as statements that bear little political weight. Statements that challenged the liberal participants' existing ideals the most caused a part of the brain called the "Default Mode Network" to light up. This part of the brain is also associated with self-reflection and identity, according to the study.

"Political beliefs are like religious beliefs in the respect that both are part of who you are and important for the social circle to which you belong," Kaplan said in a statement. "To consider an alternative view, you would have to consider an alternative version of yourself."

What does this mean?

"Understanding when and why people are likely to change their minds is an urgent objective," researcher Sarah Gimbel, a scientist at the Brain and Creativity Institute, said in a statement. "Knowing how and which statements may persuade people to change their political beliefs could be key for society's progress."

There are a couple of important caveats to note. For starters, the sample size was small (only 40 participants, all liberal), and while the scans show activity in the Default Mode Network, it doesn't let us know what's actually happening. However, the study does suggest a link between how people think about their politics and how they think about themselves. It therefore suggests that, in order to change someone's political belief, that person needs to untangle that view with how they self-identify. When someone does not feel personally threatened by someone challenging their ideals, they're less likely to stubbornly stand by their held opinions.

“If a belief becomes incorporated into our personal or social identity, then it’s much harder to change. We wanted to see what’s going on in the brain when people resist belief change,” Kaplan told Yahoo News. "If we don’t change our views as we gather new evidence, what’s the point in gathering new evidence in the first place?”