University of Cambridge professor David Spiegelhalter studies coincidences for a living.
As a researcher for the Winton program for the public understanding of risk based in the University's Statistical Laboratory, Spiegelhalter collects people's coincidence stories—everything from finding out your roommate is actually your cousin to having five friends named Carly—and analyzes them for scientific explanations.
Now, the San Francisco-based text analytics firm Quid has taken 4,470 of Spiegelhalter's collected coincidences and conducted a linguistic analysis to determine the most common themes. They visualized their findings in a map that shows the top 10 most common threads seen throughout the stories, including shared birthdays and death dates, phone number similarities, and running in to someone you know on public transit.
Here's the full visualization:
Each dot in the infographic represents a story, with the colors coded to each category. The lines connecting the dots denote that the stories have strong linguistic similarities. Most of the lines connect to stories within a given category, but a few stretch over to other neighboring categories, indicating that the story involved both types of unlikely happenstance. Coincidences involving phone number similarities, for example, often intersected with the somewhat vague "vacation happenings" category and the meetings while in transit, suggesting that revelations about phone numbers often happened in those two scenarios. Four of the top coincidence topics involved numbers (birthdays, death dates, license plates and phone numbers), suggesting dates and numbers are a popular source of what people consider to be unusual coincidences
The common types of coincidences detailed here are general; and even the definition of coincidence can be a bit murky. But on the website where Spiegelhalter collects the stories, he offers guidelines that give some insight into what the dots are about. For example:
Surprising repetitions: for instance when you’ve had not contact with someone for ages, then find two connections to them very close together in time. Or when over several years multiple members of the same family are born with the same birthday. Or even a repetition of a really rare event – like winning the lottery twice, or your life being saved twice by the same person!
Simultaneous events: for example when two people phone each other at exactly the same time.
Parallel lives: such as when two people in a small group find they share a birthday or an unusual name, or when two people discover their lives match each other in bizarre details.
Uncanny patterns: imagine picking letters in Scrabble that spell your name.
Unlikely chains of events: perhaps you lost your false teeth overboard and found them inside a fish you caught twenty years later?
Speaking to The Atlantic, the Quid researchers detailed some other results of their findings that didn't make it into the infographic. Fifty-eight percent of all the anecdotes included words related to family or loved ones, indicating that people are more likely to notice coincidences involving people closest to them. In analyzing the answers for tone, they found that more people told their coincidence stories using negative language (32%) or neutral language (41%) than positive language (25%).
More evidence that our coincidences can be downers? The word "die" appeared 373 times in the dataset—while the word "love" occurred just 220 times. Read more of Spiegelhalter's collected coincidence stories (or share your own!) by visiting the Winton Program for the Public Understanding of Risk.