How Effective Would A Foil Hat Really Be At Blocking Thoughts?

Following the 2020 presidential election in the United States, the subject of conspiracy theories came under heightened scrutiny. Of course, conspiracy theories are nothing new; the idea that there's someone, or a group, beyond what we know about and can observe, secretly controlling things, doubtless predates us by centuries. Perhaps it's human operatives controlling the government or finance, perhaps it's aliens, perhaps it's lizard people.

A joke, of sorts, has emerged from the world of conspiracy theories, a sort of shorthand for identifying someone who believes in them, perhaps too strongly: the tinfoil hat. Of course, it would be more accurate to refer to it as an aluminum foil hat, since aluminum foil replaced tin after World War II — it was cheaper and more sturdy, says Everyday Recycler. The idea goes that "they" are monitoring your thoughts, and so if you cover your head with metal — and foil is perfect for its light weight and malleability — others can't read your thoughts.

It is possible to transmit your thoughts outside of your head. As Technology Review notes, the technology is in its infancy, but science is working on some day allowing humans to communicate with each other via their thoughts. However, for now, as far as anyone knows, it's impossible to simply somehow "scan" the room where someone is and read and interpret their thoughts.

If the technology did exist (or if aliens or lizard people have it), a foil hat isn't going to do much to, uh, foil it. As Mental Floss explains, whatever you create with foil isn't going to fully cover your head to the point that nothing escapes from it. Further, as evidence of the notion that there's nothing an undergraduate won't write a paper about, a group of MIT students actually tested this, partly out of a desire to put the university's expensive scientific equipment to use. Long story short, the foil hats did precisely diddly, and in some cases even amplified the signals coming out of the brain — in other words, actually made things worse.