It is hard to know, but most likely the conspiracy theory is one of the oldest parts of human society. In fact, the popularity of conspiracy theories is probably a good measure of social trust. Low-trust societies, like you find in the Middle East, tend to be shot through with conspiracy theories. High trust societies in Northwest Europe tend to have less of it, but even they are prone to bouts of conspiracy mongering. The Great Fear that swept through rural France is a good example.
In modern times, the conspiracy theory has been formalized. The assassination of John Kennedy is probably when this formalization process began. For example, a conspiracy theory needs a series of hard to accept coincidences. In the case of Kennedy, we have the amazing marksmanship of the shooter and then his unlikely assassination at the hands of a Jewish gangster, while he was in police custody. The Jack Ruby part is what made the whole thing perfect for the conspiracy theorists.
The first step in a conspiracy theory is that the obvious answer or the official answer must be eliminated as a lie or implausible. In the case of the Kennedy assassination, the start of the conspiracy dynamic was the dismissal of Oswald as the lone actor. It is a variation on the old Sherlock Holmes line. Once you eliminate the parsimonious explanation, then the more complex and convoluted explanations become more plausible. That opens the door to endless speculation.
We see this with the QAnon cult on-line. All of it starts with the assumption that the obvious answer is wrong. For example, it is plainly obvious that Bill Barr is covering up the FBI spying scandal. He’s had years to do what should have taken a few months. Instead of accepting that rather obvious and plausible explanation, the QAnon people reject it and instead weave wildly complex theories about how half of Washington is about to be charged with crimes.
Another aspect of the formal conspiracy theory is the liberal use of the associative property to connect unrelated events. Person A knows Person B and Person B once had lunch at the same place as Person C. If any of these three people can be tied to the event in question, then it is assumed the other two are connected. The weakest associations are enough to assume a conspiracy. The associative property is an essential element of the modern conspiracy theory.
In the case of Kennedy, for example, organized crime is a popular player, because Jack Ruby was a minor criminal. His tenuous association with organized crime opens the door for linking any number of underworld characters with the assassination. It also opens the door for all sorts of theories about the Kennedy administration’s connections to organized crime. The associative property then ties communism, organized crime and the Cuba situation to the assassination.
The Z Man, “Conspiratorial Rule”, The Z Blog, 2020-10-01.
