Pernicious Political Polarization

Pernicious political polarization, our self-segregation into mutually antagonistic political camps is the biggest social challenge of our age. Even liberal democracy, which for centuries protected societies from this scourge, has succumbed. Since 2015, America has become one of the most polarized nations in the world.
Jennifer McCoy and her collaborators provide data that show that 178 countries have experienced 211 episodes of pernicious polarization since 1900. In each country, this polarization has undermined political foundations, disrupted economic activity, and torn apart communities.
Depolarization is almost always costly, often accompanied by violence and institutional upheaval. Worse, many countries never achieve social stability once they have polarized. Although 105 of the 211 episodes of pernicious polarization depolarized for an extended period (five years or more), many countries either never depolarized or repeatedly re-polarized. Armenia, for instance, has re-polarized six times since 1996. Thirty-five countries have failed to depolarize even once, including the U.S.
Political polarization benefits no one, so why does it occur so frequently and become so resistant to resolution? Why do we talk past one another when we attempt to communicate? Why do we resist compromising with people we dislike?
Everyone knows the answer to these questions. Other, less enlightened, people refuse to acknowledge reality or to listen to reason. Polarization would disappear if they just thought and behaved rationally.
Of course, we also know that others say the same about us. Ultimately, we must admit that our answers are nothing more than condemnation; a salve for our egos but not a panacea for our society.
Is there a path to political reconciliation or are we destined to remain trapped in unanswerable debate and constant conflict?
It may be that human bonds are more tenuous than we imagine.
Perhaps we cannot resolve our differences because as Philip K. Dick observed,

...each human being lives in a unique world, a private world different from those inhabited and experienced by all other humans. . . If reality differs from person to person, can we speak of reality singular, or shouldn't we really be talking about plural realities?

Maybe we do not share a common earth after all but live in parallel worlds. We cannot resolve our political differences because our minds reside in separate planes of existence. We understand the reality in our mental universe but comprehend only the vaguest notions of theirs. Communication and conciliation are impossible without comprehension.
This idea may sound like science fiction but there is, in fact, a body of evidence that suggests plural realities lie at the root of pernicious political polarization. Even if true, does this realization take us closer to a solution? The answer to that question lies in the peculiar relationship between belief and reality.