The fact that so many people eagerly embrace conspiracy theories is a sad reflection on our cognitive limitations as a species. The human brain really isn’t evolved to do much thinking, and conspiracy theories demonstrate this amply.

Let’s see why it’s so easy to eliminate 99% of conspiracy theories: we use a technique called plausibility testing. Let’s apply this basic technique to the “moon landings were a hoax” conspiracy theory.

Firstly there’s the sheer number of people involved in the decade leading up to the Apollo 11 mission. Every single one of them kept quiet for decades. Not a single person mentioned it to a partner or friend or neighbor, ever — because if they’d done so, the confidant would have been on the phone to the media in a heartbeat. How likely is this, given the typical human propensity for gossip?

More pertinently, let’s look at the context: the USA and the USSR were locked in a battle for technological supremacy. The USA tracked all the telemetry of every Soviet launch and the Soviets tracked the telemetry of every US launch. As the Soviets were desperate to win the race rather than lose it, how plausible is it that the Soviets would have kept silent about the fact there was no telemetry coming from the moon? In reality, if Apollo had been a hoax the Soviets would have spent a significant fraction of their entire budget publicizing the fact and handing out detailed proofs.

In short, as is so often the case, the USA effectively committed intellectual suicide in the pursuit of ad revenues, because garbage like the “moon landing hoax” drew in audiences and audiences meant more ad revenue. It’s a pathetically inadequate reason to undermine society but people are people so there you go.

Before we end, let’s take a look at a contemporary conspiracy theory: the con-trail conspiracy. According to its proponents, every commercial aircraft in the sky is spreading some undefined (but bad, oh yes, very bad, I mean really bad, like badder than bad, honest) chemical intended to harm everyone on the planet.

Again we have to wonder how all the hundreds of thousands of people involved in this conspiracy from the lowest-level member of the local airport ground staff to the pilots themselves manage to keep silent about this awful conspiracy for decade after decade — especially as it’s their own families and friends they’re supposed to be poisoning. And as for the poisoning, um… who’s been poisoned? With what? Where are the people reporting symptoms?

Of course it must be a conspiracy because it’s too difficult for simple people to understand the notion of ionization and condensation. I mean, that could take up to five whole minutes of reading a textbook with words of more than no syllables! And who’s going to do that heavy intellectual lifting when there’s a much easier meme to wrap that single semi-functioning neuron around?

So in the end the success of all conspiracy theories boils down to the simple fact that a great many people lack even the most rudimentary cognitive apparatus for consistency checking and plausibility checking. That’s tremendously sad, but it’s also not going to change any time soon.

And you know why not? Because there’s a conspiracy to stop it changing…