Study after study has found that partisan beliefs and bias shape what we believe is factually true.

Now the Pew Research Center has released a new study that takes a step back. They wondered: How good are Americans at telling a factual statement from an opinion statement — if they don’t have to acknowledge the factual statement is true?

By factual, Pew meant an assertion that could be proven or disproven by evidence. All the factual statements used in the study were true, to keep the results more consistent, but respondents didn’t know that.