One of the biggest conspiracy theories of recent years is also potentially the most dangerous. The belief, shared by nearly 6 percent of Americans, that vaccines — most notably those developed to protect us from COVID-19 — are not being rolled out to inoculate us against a deadly disease, but are really Trojan horses to fit each and every one of us with a tracking chip, by which the government and private companies can monitor our movements, behavior, and body chemistry.

Vaccine hesitancy is nothing new; it has been with us since the dawn of vaccination in the 19th century, per The MIT Press, but the “anti-vax” movement has gained significantly more attention since the arrival of the global coronavirus pandemic, partially due to the high profile of some believers such as rapper Kanye West, per Forbes. But anti-vax beliefs are so dangerous because vaccines only really work if a large proportion of the population is willing to take them; if widespread, such theories are deadly.

But though the cut-through of such ideas in recent years is cause for concern, they are yet to take hold of the American imagination anywhere nearly as decisively as the most legendary of cover-ups: Area 51. According to our survey, more than 35 percent of us believe — or, at least, want to believe — that in 1947 the American government covered up the crashing of an alien spacecraft in Roswell, New Mexico.