Meaningful Coincidences: How and Why Synchronicity and Serendipity Happen

The words coincide and coincidence came into English through philosophy, likely from translations from the Latin of Roger Bacon (1220-1292). The words then passed into the vocabulary of scholarly English writers during the first half of the seventeenth century and then were taken up by mathematicians during the great revival of mathematical study at that time in England.

The word coincidence became a household word in American English following the simultaneous deaths of Thomas Jefferson and John Adams on July 4, 1826. The pair died exactly fifty years after each had signed the United States Declaration of Independence.1

So then, what is a coincidence? We actually know very little about what they are. That reality is best illustrated by the dictionary definition, which states that a coincidence is the remarkable concurrence of events or circumstances without apparent causal connection. Why is it remarkable? Because they occur at the same time? Because their concurrence is surprising? Because there is no apparent cause though it seems there should be one? And left unsaid in that definition is the suggestion that the coincidence may have meaning.

The definition of coincidence harbors contradictions. There could be no cause or there could be a cause. It could have no meaning or could be meaningful. Coincidences may be both improbable and surprising, but these are not synonyms. Coincidences tend to be improbable events, but all improbable events aren’t necessarily coincidences.2 For example, rolling a die six times and getting 464255 might be just as improbable as 666666, but not nearly as surprising.3 Similarly, coincidences are usually surprising.4 But events that are surprising (e.g., an unexpected firecracker or birthday party) are not necessarily coincidences.5,6 So a surprising and improbable coincidence captures attention and seems to demand explanation.

Our attempt to understand what is meant by the word coincidence is made all the more difficult at the starting gate because the word coincidence is used in two starkly opposing ways: either as attention-worthy or as irrelevant. Adjectives used with the word coincidence sharpen the direction of the intended meaning. When coincidences are thought to be important or to have a cause, whatever it may be, the speaker will use adjectives such as meaningful, remarkable, or amazing. “That was an amazing coincidence,” one might say. When the coincidence is viewed as irrelevant, as due to chance, adjectives such as mere, only, pure, sheer, and just will modify the word. “That’s just a coincidence.” And when the word is used without a modifying adjective, the speaker’s intended meaning may be unclear: “It was a coincidence that you showed up when I did.”

But one thing about coincidences is certain: they are all around us. In our daily lives, on the internet, radio, and television, and in our entertainment; but like the gorilla in the room, we often don’t notice them, or do so only briefly, in passing, and often without giving them a second thought. The survey I conducted while at the University of Missouri in 29 found that at least a third of the general population frequently notices coincidences.7 That’s a good start and suggests to me that perhaps it’s time to create a new field to explore how these unexpected conjunctions of events can be understood. To this end, I have proposed the establishment of The Coincidence Project, which includes the transdisciplinary field of coincidence studies (see appendix 1 for more on this).

But first, let’s begin by pulling apart the threads of what’s commonly called a coincidence.

TIMELINESS

When we consider coincidences, what variables are involved? The first and most obvious one is the time interval. Coincidences are commonly viewed as the coming together of two or more events simultaneously in time, or nearly so. The instantaneous or short time interval between the coincidental events seems to increase the significance of a coincidence in peoples’ minds, because short time intervals between the occurrences of two seemingly unrelated events begin to suggest a cause. Lightning is quickly followed by thunder, so lightning causes thunder.

But, in fact, the time intervals characterizing coinciding events can vary from simultaneous to many years. And coincidental events taking place years apart can be every bit as astonishing as those that are instantaneous. Take this example as related by psychologist Alan Combs and English professor Mark Holland in their book Synchronicity: Through the Eyes of Science, Myth and the Trickster: “Allen Falby was a highway patrolman in Texas. One night on duty he crashed his motorcycle and lay bleeding to death on the road, having ruptured a major artery in his leg. At that point, a man named Alfred Smith arrived, quickly put a tourniquet on his leg, and saved his life. Five years later, Falby was again on duty and received a call to go to the scene of an auto accident. There, he found a man who was bleeding to death from a severed artery in his leg. He applied a tourniquet and saved the man’s life. Only then did he find out it was Alfred Smith, the very man who had saved his life in the exact same way five years earlier. Falby joked, ‘It all goes to prove that one good tourniquet deserves another.’”8

In the creation of a coincidence, time is generally viewed as going forward: a person thinks of something and then an event or object in the environment matches that thought. But as the Allen Falby story illustrates, coincidences can also be recognized by looking back in time and matching events retrospectively.

SIMILARITY

Another variable in coincidences is similarity: the two or more events making up a coincidence must be similar. In the Allen Falby example, both events involve a tourniquet on the leg saving the life of a man bleeding to death. That in itself is not a coincidence, but the fact the two men happen to save each other’s lives years apart without knowing or being involved with one another--and each showing up at the right place and time to save the other person’s life--is what makes it a coincidence.

It would be seen as somewhat less of a coincidence if Falby, who had been saved from bleeding to death with a tourniquet applied by Smith, had saved Smith say, from drowning, by resuscitation. And perhaps it would not be seen as a coincidence at all if they were both in the same police department; that would certainly be the case if they were patrol partners.

IMPROBABILITY

Similarity brings up the subject of statistical probability, a subject we will deal with in greater detail in a subsequent chapter 5. But as another variable of coincidences, it is also discussed briefly here. Though not stated explicitly in the dictionary definition of coincidence, it’s understood that a coincidence is an unlikely event. Finding your watch in the pocket of a coat you haven’t worn for months is not a coincidence. It’s forgetfulness. Thinking of your mother just as your mother happens to call you is not a coincidence, or at least not an unlikely one. After all, she is your mother, you probably think of her often, and she does call you from time to time.

The higher the probability of a coincidence, the more likely there is a conventional explanation for the coincidence. But the lower the probability (or the higher the improbability) of a coincidence, the less likely simple mathematical randomness can explain the concurrence, and the more likely that the cause or explanation for the coincidence lies outside the realm of conventional science.

Improbability is related to the...