"Liberals think conservatives are biased and they're objective. And conservatives think liberals are biased and they're objective," said Professor Peter Ditto, who studies human judgment and decision making at UC Irvine. "But what we find is both sides are equally biased in their own direction."
To study how morals affect political ideologies, Ditto and collaborators created YourMorals.org, a website where anyone can fill out psychological surveys related to morality. To date, over 600,000 have taken surveys on the site.
What struck Ditto was that moral beliefs aren't just affecting political opinions – more and more, our morals seem to be affecting what we perceive as fact.
"Liberals and conservatives look at the same thing and see something very different," said Ditto.
People who think that the death penalty is morally wrong also believe that it doesn't deter crime. People that support the death penalty believe that it's an effective deterrent. Scientific research does little to sway either side.
People are good at spotting bias in everyone but themselves, what psychologists call the "bias blind spot."
"The real issue in politics is a massive lack of self-awareness," said Ditto. "If you can get people to realize a little bit of humility, a little bit of recognizing that they're doing the same things that the other side is doing, maybe that will help."
Read more: When it comes to politics, you're not as rational as you think
Watch: How Morals Influence If You're Liberal or Conservative
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