Conspiracy theories seem to be more prevalent than ever, thanks to the spread of the internet and the flame-fanning of social media, but how do they spread?
The answer is more complicated than you might think, according to new research.
These far-out, implausible ideas about life, the Universe, and everything aren't solely propagated by a minority of tinfoil hat-wearing conspiracy theorists.
In fact, they thrive because people across many different groups and beliefs buy into them.
That's based on a new analysis of some 1.7 billion comments and linked metadata pulled from Reddit between October 2007 and May 2015.
The data included nearly 2.25 million comments made on r/conspiracy by around 130,000 different authors.
"It is commonly believed that conspiracy believers tend to be the kind of people that connect every conspiracy to everything else – like the typical tinfoil hat wearing stereotype," says lead researcher Colin Klein from the Australian National University.
"You have to realise it's not just people who are crazy and distrust everything. We found that there are those people, but they are the tip of a much larger iceberg."
To put it another way, the diversity in post authors that the researchers observed is evidence against one single group being behind the spread of a conspiracy theory – whether that group is tied by shared ideologies or simple irrationality.
Instead, conspiracies most often gain traction when a range of people and groups get involved in spreading it, the researchers found.
It turns out that quite a lot of us are on the look-out for conspiracies that fit agendas we already have – a conspiracy theorist is not just "someone who believes in conspiracy theories", the researchers say. It's more complicated than that.
"The most successful conspiracies were the ones where everyone can get something out of it," explains Klein. "Each gets what they need, and each contributes to the larger whole."
He cites the example of a secret CIA prison camp conspiracy – a theory like that is going to attract people interested in the 9/11 terrorist attacks, and people pushing an anti-Semitism agenda, and those passionate about gun control. It fits several agendas, and so it can take off.
The bottom line is that people don't necessarily believe in the conspiracies they're peddling – they just want to use them to make a point or promote a way of thinking.
"It's a way of expressing a dislike for something – like a politician or a group of people," says Klein.
"Pizzagate is a really interesting case, where it starts off as a form of trolling by people who didn't like Hillary Clinton, but then others were willing to pick it up seriously and take it further."
So why does this matter? Plenty of research points to the danger of conspiracy theories, and that danger seems to be increasing – that could be in relation to the injuries of a single person or the health of millions of people, in the case of the antivaxxer movement.
If experts can better understand how conspiracy theories spread and why people get attached to them, we might be able to do a better job of debunking these ideas in favour of some scientific fact.
The researchers behind the exhaustive Reddit study conclude by saying we shouldn't be looking for overarching belief systems that link conspiracy theorists – instead we should be looking at the messages they pass on.
"It is conspiracy narratives that are all-encompassing," write the researchers in their study.
"Pulling in a diverse group of people who may have little in common with one another, each of whom can find what they need in a fragment of the larger tale."
