Somewhere around 100,000 years ago our species began to develop the capacity for abstract thinking. Whereas other animals live in the real world, we live in a kind of fantasy land in which concepts shape experience. Unfortunately our brains are small and there’s never been much selection pressure to promote traits that are essential for rationality: consistency-checking (is the claim X consistent with everything else I know about the way the universe works?) and coherence (from the premise given, does the conclusion logically follow?). Furthermore, as the human brain can consume up to 30% of the body’s blood glucose, and as this would be more often required to power muscles to search for food or evade danger, we’re hardwired to do as little thinking as possible. Given these three factors it’s unsurprising that the typical person never thinks an original thought at any point throughout their lives; people simply absorb and repeat whatever they’re told by purported authority figures. Add in the fact that today we live in a world of such complexity that very few have even the vaguest grasp of how things work, and we have an ideal recipe for credulity and idiocy. Conspiracy theories are invariably (a) extremely simple to grasp, and (b) extremely incoherent with regards to known facts. Real conspiracies, conversely, usually involve several complex elements which is precisely why they can persist for a long time without being dragged into the light. So our tiny brains adore simple-minded conspiracy theories no matter how incoherent or impossible, but shy away from reality-based ideas because they’re too difficult (and often require far too much factual knowledge) to encompass.
As most people pass through the educational system without ever learning to reason (to pass tests one merely needs to memorize content, not understand it), it’s evident that many will be vulnerable to conspiratorial thinking. As people are not going to become more intelligent, and as evolution will take tens of thousands of years to effect alterations in our brains, and as our educational system promotes mostly the wrong type of learning, it’s evident that conspiracy theories and their leagues of adoring fans will be with us for a long, long time to come. And as we crave the illusion of certainty during times of confusion and fear, we’ll rush headlong toward the nearest nonsensical belief merely because we can temporarily derive some comfort from doing so. The fact that the beliefs are infantile and absurd is in no way any deterrent.