You mischaracterize the study. The interesting finding is not that people who hold anti-consensus beliefs have lower scores on objective tests about related fi

You mischaracterize the study. The interesting finding is not that people who hold anti-consensus beliefs have lower scores on objective tests about related fields. It's that they are willing to bet more on their performance on those objective tests despite ultimately scoring worse. That is, there's a much larger difference between their subjective assessment performance and objective performance on the test metric (of both that field and other fields) than in people who don't hold the anti-consensus belief.