This is not a new story, but it is worth repeating. At the moment that bullets were being fired into JFK’s motorcade, a man can be seen standing on the side of the road near the car holding an open black umbrella. It was a sunny day (although it had rained the night before) and no one else in Dallas was holding an umbrella.
This is exactly the kind of detail that sets a fire under conspiracy theorists. It is a genuine anomaly – something that sticks out like a sore thumb.
The event also defies our intuition about probability. Even if one could accept that somewhere on the streets of Dallas that morning one man decided to hold an open umbrella for some strange reason, what are the odds that this one man would be essentially standing right next to the president’s car when the bullets began to fly?
Our evolved tendency for pattern recognition and looking for significance in events screams that this anomaly must have a compelling explanation, and since it is associated with the assassination of a president, it must be a sinister one.
When you delve into the details of any complex historical event, however, anomalies such as this are certain to surface. People are quirky individual beings with rich and complex histories and motivations. People do strange things for strange reasons. There is no way to account for all possible thought processes firing around in the brains of every person involved in an event.
Often the actions of others seem unfathomable to us. Our instinct is to try to explain the behavior of others as resulting from mostly internal forces. We tend to underestimate the influence of external factors. This is called the fundamental attribution error.
We also tend to assume that the actions of others are deliberate and planned, rather than random or accidental.
The common assumption underlying all of these various instincts is that there is a specific purpose to events, and especially the actions of others. We further instinctively fear that this purpose is sinister, or may be working against our own interests in some way. In this way, we all have a little conspiracy theorist inside us.
*Who Was the Umbrella Man?
Every skeptic’s new favorite website is Spurious Correlations. The site is brilliant – it mines multiple data sets (such as causes of death, consumption of various products, divorce rates by state, etc.) and then tries to find correlations between different variables. The results are often hilarious.
The point of this exercise is to demonstrate that correlation does not necessarily equal causation. Often it is more effective to demonstrate a principle than simply to explain it. By showing impressive looking graphical correlations between phenomena that are clearly not related (at least proposing a causal connection superficially seems absurd.), it drives home the point that correlation is not enough to conclude causation.
I think most people can intuitively understand that funding on science, space, and technology is unlikely to have a meaningful causal connection to suicide by hanging, strangulation, or suffocation.
Yet – look at those curves. If a similar graph were shown with two variables that might be causally connected, that would seem very compelling.
There are a couple of points about this I want to explore a bit further. First is the important caveat that, while correlation is not necessarily causation, sometimes it is. Two variables that are causally related would correlate. I dislike the oversimplification that is sometimes presented: “correlation is not causation.” But it can be.
The second point is a statistical one. The important deeper lesson here is the power of data mining. Humans are great at sifting through lots of data and finding apparent patterns. In fact we have a huge bias toward false positives in this regard – we find patterns that are not really there but are just statistical flukes or complete illusions.
Correlations, however, seem compelling to us. If we dream about a friend we haven’t seen in 20 years then they call us the next day, that correlation seems uncanny, and we hunt for a cause. We aren’t even aware of the fact that . . .