We weren’t surprised to find that views about the air-pressure scandal differed by team loyalty, but the degree of polarization was remarkable. Beliefs about the controversy divide Patriots fans and supporters of other N.F.L. teams as sharply as the myth that President Obama was not born in this country splits Democrats and Republicans. Only 16 percent of Patriots fans said that Brady broke the rules, compared with 67 percent of fans of other teams (including 90 percent of Colts fans).

By comparison, 56 percent of Republicans in our sample endorsed the so-called birther theory that President Obama wasn’t born in this country, versus only 8 percent of Democrats. (For those who haven’t followed that one: Mr. Obama was born in Hawaii, our 50th state.)…

As these results suggest, knowledge had no consistent relationship with beliefs among fans of other teams. Among Patriots fans, however, fans were more likely to believe in Brady’s innocence when they knew more about the controversy — a pattern we’ve also observed in factual controversies in politics. In both sports and politics, people who know more are often more motivated to cling to their views and better able to defend those beliefs when challenged.