The greatest scientific hoax was the "Piltdown Man", "discovered" in a quarry in southern England in 1908. It was the "Missing link" in the fossil record, a skull with the brain of a man but the jaw of an ape.
Of course, it was all fake. It was assembled and hidden at the Piltdown site by person or persons unknown, but on this day in 1953 the British Museum formally announced that it was not genuine.
For fourty years, the scientific community had been taken in by a clever assembly of piece parts designed to play to current accepted scientific theory. The parts never really fit together well, and the story didn't fit together very well either, but the scientific establishment welcomed Eoanthropus dawsoni with open arms. Backed by the power of the consensus, Piltdown Man was "settled science" for four decades.
Scientists wanted to believe in it. It fit the current theory, National pride made it agreeable to swallow, and so many scientists didn't look too closely at the data or demand too many consistencies. It was comfortable.
And it was a fake. Confirmation Bias comes from many places, but all examples - all of them, including the too eager acceptance of Anthropogenic (human-caused) Global Warming - have something in common. People don't look too closely at the data, because it result is one they like. Too close an examination of the data might raise questions, harshing their mellow.
Piltdown Man, rest in peace. May we learn from you the need for eternal vigilance, against our own desires most of all.