How common are doppelgÀngers?
Perhaps youâve heard the saying, âEveryone has a twin somewhere in the world.â Not a biological twin (although some people do have one or more of those) but a person who bears an uncanny resemblance to an unrelated stranger. English speakers call these kinds of twins âlook-alikes.â In German the term is doppelgĂ€nger (literally, âdouble goerâ). DoppelgĂ€ngers are common in literature, horror movies, and folklore. But how common are they in real life?
The answer is: not at all common. According to a 2015 study by researchers in Australia, thereâs less than a one in a trillion chance that someone out there looks exactly like you. These odds were determined by examining the facial measurements of nearly 4,000 individuals in a database of military personnel. The researchers estimated the probability of matching facial measurements among the group by comparing eight specific metrics, such as the length of the ears or the distance between the eyes. They found that the probability of two people with matching measurements for all eight traits was to the order of 10-14, or one in a trillion.
However, if you lower your standards a bit, thereâs hope for finding someone out there who looks a lot like you, if not just like you. The study determined that the probability of two people with matching measurements for four of the facial traits is to the order of 10-7, or one in 10 million.
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Yet, some scientists donât agree with these findings. A common argument is that people perceive things differently, including faces. Some people may see similarities in two faces other than the metrics used in the study. Plus, you may have a doppelgĂ€nger who lived before your time or one who is yet to be born.
So yes, if youâre seeing double when you look at pictures of 21st-century actor Jack Black and 18th-century patriotic folk hero Paul Revere, youâre likely not just seeing things.