We Americans love jury trials, in which an accused person is judged by a group of peers from the community. Every citizen, when called, must sit on a jury. For anyone who finds this civic duty a painful chore: Go watch12 Angry Men, A Few Good Men, or any episode of Law & Order. You’ll feel all warm and fuzzy with the knowledge that, though juries don’t always make the right call, they’re our best hope for carrying out justice.
But…what if they aren’t? Juries are made of people. And people, as psychologists and social scientists have reported for decades, come into a decision with pre-existing biases. We tend to weigh evidence that confirms our bias more heavily than evidence that contradicts it.