This article is from the archive of our partner National Journal

Republicans and democrats don't see eye-to-eye on many issues. But why? National Journal's Brian Resnick has the biological answer.

For more, read National Journal's "How Politics Breaks Our Brains, and How We Can Put Them Back Together."

This article is from the archive of our partner National Journal.

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.