Do Doppelgangers Exist? The Probability Stands at 1 in a Trillion

The likelihood of having an unidentified twin is extremely slim. Toshiro Shimada/Getty Images

Do doppelgangers truly exist? They definitely do in the horror film "Us" and the countless evil-doppelganger storylines found in soap operas.

If this were reality, your identical counterpart could be out there, dressed just like you and mirroring your grin, ready to seize your life without your partner, employer, or closest friends noticing.

What Is a Doppelganger?

The term "doppelganger" originates from German, translating to "double-goer" or "double walker," referring to someone who bears an uncanny resemblance to you. Unlike identical twins who are genetically linked, a doppelganger is unrelated yet mirrors your facial characteristics.

In popular media, doppelgangers are frequently portrayed as malevolent figures, often associated with misfortune. As noted by

Vulture, television and movies have employed these lookalikes to explore the duality of good versus evil: "In shows like 'The Leftovers' and 'Twin Peaks,' the trope underscores the interconnected nature of good and evil."

What Are the Odds You Have a Doppelganger?

For those who are easily spooked, there's good news: statistically, the likelihood of encountering a doppelganger who shares your exact facial features is nearly nonexistent. Rest assured, the risk of mistaken identity is minimal.

"When it comes to facial measurements, the probability of two or more individuals matching across eight facial dimensions is 1 in a trillion," explains Dr. Teghan Lucas, a forensic anthropologist at The University of New South Wales and Flinders University in Australia, via email.

In 2015, she conducted a study on doppelgangers, comparing individuals based on eight facial and eight body measurements to determine their similarities. Among the meticulously detailed measurements were ear length, head circumference, and the distance between the centers of the right and left pupils.

While this explanation may offer reassurance, if it doesn’t, consider that Lucas’s findings regarding the rest of the human body revealed even slimmer odds of encountering a lookalike.

"When examining body measurements, the likelihood drops to 1 in a quintillion, based on eight measurements," she states. "This is due to the larger range of these measurements, making it even less probable for individuals to match."

Therefore, the more measurements you analyze, the lower the chance of finding a perfect match in true doppelganger form. "Two people might appear strikingly similar at a glance, but upon measurement, they won’t align," Lucas notes.

Anecdotal Experiences

Even with these improbable odds, many people have encountered situations where a stranger mistakes them for someone else or claims they resemble an unknown twin. This makes it easy to entertain the idea of doppelgangers.

"Most of the individuals we perceive as doppelgangers are those we aren’t closely familiar with," says Dr. Michael Sheehan, a neurobiologist at Cornell University.

"You’re far more likely to spot a lookalike of an acquaintance than your own mother. You know your mother intimately, so even if someone resembles her, you’d quickly notice the differences," he explains, emphasizing that familiarity makes it easier to detect discrepancies.

"There’s only so much variation in human appearance," he notes. "Some individuals are bound to look alike purely by chance."

Practical Applications for Further Research

Even though doppelgangers are highly unlikely, researchers continue to delve into the study of body characteristics and their unique traits.

Subtle variations in human features are gaining significance in forensic science, as highlighted by Lucas and her team in the International Journal of Legal Medicine study.

"We examined whether facial features were the most reliable for identification and discovered they weren’t; body measurements are actually more distinctive," Lucas states. "This is particularly valuable in criminal cases where suspects, such as bank robbers caught on CCTV, often conceal their faces. We needed to determine if the body could be used as effectively as the face for identification, and it can!"

Even if you encounter someone who bears a striking resemblance, factors like aging, hairstyle, and other variables will likely diminish any true doppelganger effect.

"When I was growing up, one of my younger brothers looked exactly like me at the age of 3," says Cornell's Sheehan. However, time has changed that. "We still share some resemblance, but we’re no longer identical."