Look at today’s Internet with the right lens, and you can watch a conspiracy theory being born: While scientists are increasingly convinced that Zika virus is behind an uptick of the birth defect microcephaly in Brazil, an Argentinian activist group Physicians in the Crop-Sprayed Towns has blamed—perhaps not surprisingly—spraying. In this case, the activists are blaming insect killers called larvicides. Bonus conspiracy points! The larvicide vaguely has to do with ag-chem company (and perpetual badguy) Monsanto.

The group’s speculation spread. Small online news sites covered it over the weekend, and then on Tuesday, the *Washington Post *published a story. Here is a secret about journalism: Headlines that are questions are for butt-covering. Case in point: “Could chemicals—rather than the Zika virus—be to blame for birth defects in Brazil?”

More bonus points! A celebrity tweeted it out.

Look, it’s almost certainly not a Monsanto larvicide hurting kids. But the fear is understandable. “Zika is a good one for conspiracy theories because there’s a lot of uncertainty. It hasn’t been proven and there’s this absence of information,” says Rob Brotherton, the author of *Suspicious Minds, * a book about why people believe conspiracy theories.

Since scientists can’t yet definitively link the virus to microcephaly, the information vacuum has brought out all the usual bogeymen. The Monsanto larvicide conspiracy has made it the furthest into the mainstream press. (In fact Monsanto doesn’t make the larvicide, and the larvicide is not dangerous to humans, and even the latter half of the *Washington Post *story backtracks—classic move after a question-hed.) But … then it must have been genetically modified mosquitoes released by scientists! (Nope.) Vaccines! (Nope.) The Rockefellers! (Yeah still no.)

You know what doesn’t work to convince true believers that a conspiracy is not afoot? Thorough debunkings. These ideas persist not so much despite evidence to the contrary, but because of it. “Conspiracy theories are to some extent wired into our brains with the biases and shortcuts in the way we think,” Brotherton says. “Conspiracy theories resonate with these biases in our intuitions.”

One of these biases is called proportionality bias. “When something big happens in the world, we look for big explanations,” says Brotherton. For example, it’s hard to believe that President Kennedy’s assassination—with all its political repercussions—could have been the work of one lone gunman. So you end up with the grassy knoll, the umbrella man, weird bullet trajectories, and so on. Similarly, it can be hard to believe that an invisible virus can all of sudden cause very visible brain defects in babies.

Reading intention into disaster is another source of bias. “People need somebody tangible to blame and give them a target for their anger, rather than have something that happens by happenstance, by chance, by force of God, or by force of nature,” says Ted Goertzel, a retired sociologist at Rutgers University who has studied conspiracy theories in science.

But a virus? Whom do you blame?

And once someone has become suspicious about the government or corporations—even for legitimate reasons—those suspicions are hard to shake. That’s why the same bogeymen come up again and again. Confirmation bias means that people tend to dismiss the information that contradicts their worldview as yet more evidence of conspiracy. Like anytime I point out that GMOs can have benefits, I get dismissed as a shill for Monsanto. (Hello, comments section of this story.)

Given that conspiracy theories grow in the dark corners of our brain, the way to combat them isn’t always with debunking them with the overwhelming facts, says Viren Swami, a psychologist at Anglia Ruskin University. Swami has done research that suggests people fare better against conspiracy theories when armed with better analytical tools. In one study, students who took a course with the book Critical Thinking Skills ended up being less conspiratorially minded. Make people aware of their cognitive biases, and they draw their own more logical conclusions.

And it’s hard to argue against critical thinking, right? Unless, of course, *Critical Thinking Skills *is all part of a conspiracy to brainwash us into swallowing the party line...