[…] Another fact is that our brains were made — or rather, evolved — to learn. We learn through trial and error. We learn by observing and inferring patterns. Emotions strongly influence our decisions. And that is not a bad thing. When we learn a pattern, dopamine is released in the brain, creating a feeling of pleasure. We like to discover the pattern of things, to try to predict future events.

In an experiment with monkeys, where we ring a bell and then give them a banana, the monkey learns the pattern “after the bell comes the banana”. They learn this, and we can measure the dopamine being released when the bell is rung, because the monkey learns to predict this event. If we turn on a light, ring the bell and then give them a banana, the monkey learns that the “light” event is followed by the bell and then the banana. This can be repeated over several steps, and the monkey learns the pattern. However, if we follow the pattern and the banana does not come at the end, the monkey actually becomes sad, because the prediction did not work.

We work like that too.

For many simple events, with few variables, this will work well. Perhaps that is why many people like routines, where the results are well defined. Our brain, however, has a flaw: in its eagerness to find patterns, the brain will try to fit patterns where none exist. This is how superstitions are born. Before we understood meteorology, primitive tribes thought that the fact “raining” was related to a dance they had just done. Therefore, they imagined that if they repeated the dance, it would rain again.

On my other blog, I translated an article from Scientific American demonstrating how we are “mathematically ignorant.” We try to find a pattern for everything. An excerpt that illustrates our superstitions and explanations about coincidence is this:

It is always possible to combine random data and find some regularity. A very well-known example is the comparison of coincidences in the lives of Abraham Lincoln and John Kennedy, two presidents with 7 letters in their last names, and elected 100 years apart, 1860 and 1960. Both were assassinated on a Friday in the presence of their wives, Lincoln in Ford Theatre and Kennedy in a Ford automobile. Both assassins had 3 names: John Wilkes Booth and Lee Harvey Oswald, with 15 letters in each full name. Oswald shot Kennedy from a warehouse and ran to a theatre, and Booth shot Lincoln in a theatre and ran to a type of warehouse. Both of their successors as vice presidents were Southern Democrats and former senators named Johnson (Andrew and Lyndon), with 13 letters in their names and born 100 years apart, 1808 and 1908.

But if we compare other relevant attributes we fail to find any coincidences. Lincoln and Kennedy were born and died on different dates (day and month) and in different states, and none of the dates is 100 years apart. Their ages were different, as were the names of their wives. Of course, if any of these were to match they would be on the list of “mysterious” coincidences. Anyone with a reasonably eventful life can find coincidences between them. Two people meeting at a party often find striking coincidences between them, but what they are — birthdays, hometowns, etc. — is not predicted in advance.

The real world is full of randomness. It is not hard to find patterns in them. In fact, it is very easy. In the real world, complex situations have many random aspects. The real world is much more random than we think. And our brains have not evolved enough to feel truly comfortable in a completely random world.