Late November traditions in the U.S. go beyond turkey and football. At this time each year, old and new JFK conspiracy ideas are floated. This is the only conspiracy theory that the majority believes. It’s a fairly strong majority, too, with 61 percent in the latest Gallup poll saying they believe.

Of course, such numbers are irrelevant to what happened. No amount of belief makes anything true. But these numbers do shed some light on how conspiracy theories operate. Because the reason JFK assassination theories have the most believers is not because of evidence. More than 50 years and hundreds of books and videos later, not one irrefutable piece of proof has been presented. Rather, so many believe because of the momentous nature of the event: The head of the free world at the height of the Cold War was murdered in public in the presence of his wife. And it’s all pulled off by a barely employable drifter. People want to believe there is more there.

Another factor in so many believing is that there are dozens of sub-theories to choose from. This is made still easier in an era when anyone with a laptop and camera can present their ideas to the world in what skeptic leader Dr. Steven Novella calls “the cottage industry of conspiracy theorists.”

There is one question about the assassination that has always bugged me: What the hell is up with the failure to secure a tall building on a presidential motorcade route? But this question is about Secret Service laxity, not a suggestion that Kennedy’s protective detail was in on the plot. But if I was a conspiracy theorist, the unsecured schoolbook depository would be used, through the appeal to ignorance, as a point for my position. That’s how conspiracy theories work. Also, if the theorist is unable to present strong evidence, that’s proof the evidence has been hushed up. If contrary evidence is presented, it was fabricated. Those presenting strong counterarguments are shills or insiders.

But perhaps the most telling distinction among hardcore conspiracy theorists is what Novella calls “anomaly hunting,” where believers look for anything that might seem out of place. In the most extreme cases, the theorist goes in already convinced that the shooting, derailed train, or natural disaster is fake. In the wake of the on-air murder of TV reporter Alison Parker, some theorists were declaring her widower to be an actor. They said he was not emotional enough for someone who had lost his wife 36 hours prior. This supposed stolidity was presented as proof that no one was murdered. This overlooks the fact that grief is a rollercoaster. A person can be laughing at a memory of a loved one, then three minutes later be convulsing because they are crying so forcefully. The burden of proof is always on the one making the claim, and the vultures in these cases spectacularly fail to prove their point.

In most conspiracy theories, the conclusion is reached first, then the theorist works backward from there. For example, they will watch a press conference or memorial service and seek out ANYTHING that looks funny to them. They always find something, owing to their nonexistent standards. The most extreme of the extreme is nodisinfo.com. At a memorial for the Charleston church shooting victims, a woman seemed to have a hint of a smile and this was presented by nodisinfo as proof it was all fabricated. For good measure, she was said to look Jewish, proving the Zionists were behind the hoax. Then there was the YouTube video is which the fact that a spectator was looking at the sky after the Space Shuttle Challenger had already fallen was proof it was the Free Masons had staged it.

These two examples are especially silly, but others can seem a little more plausible when apparent anomalies are highlighted. These are easy to find because hundreds of people and thousands of actions can be involved in such incidents, so it would be impossible to fully explain every detail to the minutest point. This is especially true in times of extreme chaos, such as 9/11, the Oklahoma City bombing, or mass shootings. Also, everyone has their quirks and complexities, so not all people will not react the same to the situation around them, making supposed inconsistencies easier to find. Throw out enough of these and something may stick, especially if the listener wants it to.

For instance, there is a meme showing a falling Twin Tower that includes a window blowing out a few stories below the main collapsing cloud. A theorist had inserted a red arrow next to the smaller cloud and wrote, “Oops. We set this bomb off too soon.”

This could be the result of unequal pressure and it seems reasonable that it would be less than perfectly uniform when a massive building soaked with jet fuel collapses. Since I’m not completely sure about the specific reason for the smaller cloud is, the theorist can appeal to this ignorance and claim it has evidence for  his position. But he’s ignoring that the burden of proof is still on him to prove that it was done by Bush or Jews or Free Masons.

By contrast, NatGeo aired a multi-hour special that detailed the bin Laden plot. This included released documents and interviews with national security personnel, plus airport camera shots of the hijackers boarding the planes and telephone calls from victims to family members relating that Muslim extremists had commandeered the aircraft.

While we’re at it, I never understood what these bomb theories were supposed to mean anyway. Even if it the towers were brought down by explosives, how does that prove they were planted by government agents instead of terrorists?

Getting back to JFK and anomaly hunting, one supposed inconsistency centers on a photo of Lee Harvey Oswald holding the rifle used to kill Kennedy. I’m unsure why the theorists are fixated with this. Of the dozens of theories I’ve heard, none have claimed that Oswald didn’t do it. Rather, he’s presented as a stooge or lackey, a pawn in an Illuminati Bilderberg Cosa Nostra Commie Nazi game. But for whatever reason, the theorists chose this hunting ground to try and bag another anomaly.

The main points when claiming the photo is fake are allegedly inconsistent shadows and asserting that Oswald is positioned strangely, supposedly indicative of him being added to the shot.

With regard to the latter, it’s hard to guess precisely how a three dimensional object will look on a two dimensional image. Or it was until researchers at Dartmouth published a computer analysis of the photo. They created a 3-D reconstruction of the image, including Oswald’s skeleton and skin. They distributed the weight throughout his body, copied his stance, and determined his center of gravity. They concluded that his center of gravity was within his base of support, meaning his stance was stable. They also reconstructed the lighting and camera angle, and demonstrated that the shadows were consistent.

For the hardcore believer, this is easy to dismiss. Dartmouth merely works in conjunction with the CIA, Castro, and the mafia. For the more reasonable, the explanation will likely suffice, but this case shows how time-consuming it can be to do battle with conspiracy theories. It takes five seconds assert that Oswald or his shadows are fake. It takes five weeks to refute it.