“A man with a conviction is a hard man to change,” Festinger, Henry Riecken, and Stanley Schacter wrote in When Prophecy Fails, their 1957 book about this study. “Tell him you disagree and he turns away. Show him facts or figures and he questions your sources. Appeal to logic and he fails to see your point … Suppose that he is presented with evidence, unequivocal and undeniable evidence, that his belief is wrong: what will happen? The individual will frequently emerge, not only unshaken, but even more convinced of the truth of his beliefs than ever before...”I was reminded of the history of stomach ulcer research and the difficulty that discoverers of H. Pylori had in convincing the medical establishment that ulcers were caused by a bacteria, not stress, stomach acid, or spicy food. The widely held belief that no bacteria could survive in the stomach and that there was no bacterial factor involved in this disease persisted for years in spite of the unambiguous results of the studies.
Believing (about anything) that "the science is settled" is a spectacularly good way to put on the blinders.