I recently watched the NOVA episode “Cold Case JFK” in which they focused on the scientific data surrounding the assassination of President John F. Kennedy. What they found was evidence that supports the Lone Gunman conclusion espoused by the Warren Commission. Forensic ballistics experts analyzed the gun, the bullet and it’s trajectory. They demonstrated how one bullet could have hit President Kennedy and then gone on to injure Governor Connelly in three separate places. Acoustical experts discussed how it is extremely difficult to tell where gunshots originate in an urban environment. Forensic anthropologists showed how President Kennedy’s body could list backwards and to the left if he were hit from behind. Computer experts did a 3-D laser re-creation in which they disproved the idea of someone shooting from the Grassy Knoll because the wounds simply were not consistent with being shot from that position.
The episode also discussed some of the mistakes made early on that contributed to the confusion surrounding the assassination. For 
example, it was pointed out that the two military doctors at Bethesda who did the autopsy were not forensic experts and thus had little experience in making conclusions of that kind (especially given the limitations they had to endure). The forensic ballistics experts explained that the rifle used was not one that was generally used, so the authorities at that time, including the FBI, were not as familiar with it.
The episode did a good job of dispassionately analyzing the evidence. Unlike other documentaries of the Kennedy assassination, NOVA did not speculate on Lee Harvey Oswald’s motives for shooting the President, why Jack Ruby killed Oswald or even mention New Orleans District Attorney Jim Garrison’s 1969 trial in which he charged a man for conspiring to kill JFK (the accused was acquitted in less than an hour). And while I realize that the actions of the people involved are questionable, if you focus solely on the science, as NOVA did, the evidence for a lone gunman is compelling.
I am aware that many people do not feel the same way. I can certainly understand their skepticism because I used to disbelieve the official story as well. However, once I realized that (human nature being what it is) someone would have talked long before now, I became more open to the idea of there not being a conspiracy. And after I watched the science of what occurred, I became an official convert to the Lone Gunman theory.
This started me thinking about conspiracy theories in general. Why do conspiracy theories take such hold of the public imagination? The obvious answer is that there is significant distrust of the government. This is certainly true (and there are good reasons for people to be suspicious of politicians) but it has to be about more than distrust.
One possible reason for conspiracy theories is that people have a tendency to rely upon their senses even when they shouldn’t. When we think we have seen or heard something, it is very difficult to convince us otherwise because that was our experience. (“Don’t tell me it wasn’t there! I know what I saw!”) However, what we do not take into account is the myriad ways in which our senses can be fooled. After all, our sensory experience is filtered through our brain which provides interpretations based on our point of view, our rationale for what we’re experiencing, and even our expectations. That is one reason why social psychologists do not put much weight on eyewitness testimony; it is notoriously unreliable.
Take many of the optical illusions that we have. In the famous artistic example of perspective, some people will immediately see an old woman while others will see a young lady. Or just go look at the moon. When it’s high in the sky, it looks small. When it is lower in the horizon and is surrounded by other objects, it looks enormous. How big the moon looks depends upon your perspective.
Or consider how people label what they hear. If people who are used to guns hear a shot, they will automatically assume it came from a gun. However, people unfamiliar with guns who hear the same thing may believe it was a car backfiring or a firecracker. Thus, what you decide you hear depends upon your expectations.
This unreliability of sensory information can explain some of what happened when JFK was shot. People who heard the gunshots thought they heard more than three shots. But what they didn’t account for was the reverberations off buildings and the two waves of sound (a crack and a bang) that occur following a gunshot. Similarly, when a body is hit by a bullet, you expect that the impact will make it go in the direction it was hit. But that is not what experts claim transpired.
The fatal third shot caused JFK’s body to go backward and to the left. Thus, it looked as though the gunshot came from in front of him rather than behind. However, what forensic anthropologists point out is that the pressure wave created by the bullet in JFK’s brain caused a massive amount of nerve stimulation which resulted in an arching of the back versus the leaning forward we would expect to see. Thus, the anatomical workings of the body ran contrary to our expectations and people started to doubt.
Another reason for conspiracy theories is that people don’t want to believe in the whims of fate; they don’t wish to accept that the universe isn’t always structured in the way they want it to be. At the time of his death, many people saw JFK as a young, energetic visionary, someone who would change the world for the better. As such, no one wanted to believe that an average disgruntled schlub like Lee Harvey Oswald could murder a great man with a cheap rifle just because he wanted to. No one wanted to think that our beloved leader could be killed by a man who was just dissatisfied with life; it had to be something much larger in scope that brought down the President of the United States! And the same type of thinking — that it had to be caused by something big — could be said of many other assassinations and significant violent events.
Yet history is replete with stories of regular people who dramatically altered the course of history for stupid reasons. Many assassins were men who could not find a place in the world and turned to extreme political philosophies to justify their horrible crimes. A lot of them thought they would be revered and/or otherwise rewarded for their actions. What it comes down to though is that no one is truly safe and sometimes unremarkable people can impact history just because they tried. We must live with this.
While it is good to critically assess what we are told, conspiracy theories can have an element of danger to them. They sometimes depend too much on things that are unreliable, like our senses and expectations. They often do not account for people’s general stupidity or failure to act rationally in the face of crisis. And conspiracy theories can lead to obsession and an intense concentration on what could have happened versus on what is.
We will never know what truly happened on a sunny November day in Dallas 50 years ago but conspiracy theories will not change this. Perhaps it is time for us to let it go.