Only 6% of Americans believe the Moon landing was a hoax. They're the trannies of their generation. They're people who feel like they are somehow special, somehow smarter than everyone, but are unable to prove either. So they start believing in conspiracy theories. This gives them a psychological construct that reinforces their belief that they're smarter than everyone else even while lacking any substance for such a belief. Their delusion is their evidence.
The biggest predictor of a person believing that the Moon landing was a hoax is a pre-existing belief in another conspiracy theory, such as cover ups of extraterrestrials, the JFK assassination, or the existence of the Loch Ness Monster and other forms of cryptozoology.
The second biggest predictor is the combination of an IQ in the 105-115 range and having earned a GED.
Though many would expect schizophrenia is be the biggest predictor, it is actually only the third biggest predictor of belief that the Moon landing was a hoax.
While it isn't uncommon for a person to have multiple predictor attributes, there is a surprisingly large amount of clustering within the three attribute groups and much less overlap between groups than is typical for such subpopulations.
