Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!


Forgot your password?
Earth Crime Privacy Security Software The Military United States News Science Technology

Do You Have A Living Doppelgänger? (bbc.com) 142

HughPickens.com writes: Folk wisdom has it that everyone has a doppelganger; somewhere out there there's a perfect duplicate of you, with your mother's eyes, your father's nose and that annoying mole you've always meant to have removed. Now BBC reports that last year Teghan Lucas set out to test the hypothesis that everyone has a living double. Armed with a public collection of photographs of U.S. military personnel and the help of colleagues from the University of Adelaide, Lucas painstakingly analyzed the faces of nearly four thousand individuals, measuring the distances between key features such as the eyes and ears. Next she calculated the probability that two peoples' faces would match. What she found was good news for the criminal justice system, but likely to disappoint anyone pining for their long-lost double: the chances of sharing just eight dimensions with someone else are less than one in a trillion. Even with 7.4 billion people on the planet, that's only a one in 135 chance that there's a single pair of doppelgangers. Lucas says this study has provided much-needed evidence that facial anthropometric measurements are as accurate as fingerprints and DNA when it comes to identifying a criminal. "The use of video surveillance systems for security purposes is increasing and as a result, there are more and more instances of criminals leaving their 'faces' at a scene of a crime," says Ms Lucas. "At the same time, criminals are getting smarter and are avoiding leaving DNA or fingerprint traces at a crime scene." But that's not the whole story. The study relied on exact measurements; if your doppelganger's ears are 59mm but yours are 60mm, your likeness wouldn't count. "It depends whether we mean 'lookalike to a human' or 'lookalike to facial recognition software,'" says David Aldous. If fine details aren't important, suddenly the possibility of having a lookalike looks a lot more realistic. It depends on the way faces are stored in the brain: more like a map than an image. To ensure that friends and acquaintances can be recognized in any context, the brain employs an area known as the fusiform gyrus to tie all the pieces together. This holistic 'sum of the parts' perception is thought to make recognizing friends a lot more accurate than it would be if their features were assessed in isolation. Using this type of analysis, and judging by the number of celebrity look-alikes out there, unless you have particularly rare features, you may have literally thousands of doppelgangers. "I think most people have somebody who is a facial lookalike unless they have a truly exceptional and unusual face," says Francois Brunelle has photographed more than 200 pairs of doppelgangers for his I'm Not a Look-Alike project. "I think in the digital age which we are entering, at some point we will know because there will be pictures of almost everyone online.
This discussion has been archived. No new comments can be posted.

Do You Have A Living Doppelgänger?

Comments Filter:
  • No (Score:5, Funny)

    by Tablizer ( 95088 ) on Friday July 15, 2016 @11:36PM (#52522629) Journal

    I'm an asshole, why would I want to meet another me?

  • by Tumbleweed ( 3706 )

    Not a _living_ one.

  • Cops hassled me, thought I was him. He had a 'colorful' life. Almost got dragged in and fingerprinted, eventually they were convinced. The car was registered to me and my doppleganger could have never afforded it.

    Later I met his sister, found out he died. She was freaked out by me. She was a freak show all her own.

    No I didn't fuck her.

  • by penguinoid ( 724646 ) on Friday July 15, 2016 @11:52PM (#52522681) Homepage Journal

    the chances of sharing just eight dimensions with someone else are less than one in a trillion. Even with 7.4 billion people on the planet, that's only a one in 135 chance that there's a single pair of doppelgangers.

    Francois Brunelle has photographed more than 200 pairs of doppelgangers

    Maybe his math stinks and he decided to pretend that all the variables are independent because that's easier than reality.

    • Even worse, why does it smell to me like ignorance of the good old birthday paradox? Doesn't that work the same way?
      • by bondsbw ( 888959 )

        I was thinking the same thing. If I calculate it correctly, that means it only takes a group of about 1.2 million people to have a 50% chance of having a single doppelganger pair.

        • I was thinking the same thing. If I calculate it correctly, that means it only takes a group of about 1.2 million people to have a 50% chance of having a single doppelganger pair.

          I couldn't find the paper in a quick search, but this smacks suspiciously of poor journalism.

          The researcher probably stated "1 in a trillion that *you* have a doppleganger", and the journalist extended it erroneously.

          There's a further complication, in that we don't know the distribution of values within any measurement, nor the granularity.

          Measurements of distance between eyes might be gaussian, so their system could have a range of 100 values, but a handful in the middle are much more common than the outli

          • by MrL0G1C ( 867445 )

            ^ mod up, spot on.

          • by Znork ( 31774 )

            Of course, if the system actually uses a resolution that accurate, it's quite likely you won't even be your own doppelganger. Retaining water would be enough to throw it off.

            I'd wager that evolution and neural net learning has struck a pretty optimal balance between false positives and false negatives for this in the human brain.

            Oh, and the human system definitely uses measures the researchers didn't take in this study; ever failed to recognize someone because they're not in the same context you usually see

      • by taustin ( 171655 )

        I can't help but wonder if he owns stock in a company that makes biometric identification stuff, like facial recognition. Which, typically, runs about 80% accurate (which is to say, when you're looking for the 1% who are criminals, you'll get 20 false positive for every true positive, and another word for that is "useless.")

        • you'll get 20 false positive for every true positive, and another word for that is "useless.")

          Not necessarily true. If someone is murdered, and a biometric test identifies 20 suspects, and 19 of them live in other states, but one is the next door neighbor on whom the victim had a restraining order, then that is useful information.

        • A slashvertisement? Here, on adsdot! Shocked, I am, shocked!

        • by Alomex ( 148003 )

          Not at all, a composition of independent tests that have high false positives is still very useful. Search engines are an example of such. They collate weak signals with high false positives into a single ranking function, and if many of them give high values then the chances that you now have a false positive are rather low.

          People who are often surprised about this at first, but if you think about it just for a little while, it makes sense.

      • Didn't sound right to me either, but I calculated it out and it is correct.
        • What is correct? Surely not a claim of "if there's a one in trillion chance of a random person being your doppelganger, then there's 1:135 chance of a population of 7.4e9 people including at least one pair of doppelgangers". Because that's trivially wrong.
    • by Qzukk ( 229616 )

      What do you mean people don't come with both ears on one side of the head? Dammit, now I have to redo all my math, and there's half my results out the window. Next thing you know, someone's going to tell me the nose always comes between the eyes!

      • What do you mean people don't come with both ears on one side of the head?

        Take a look at something from Picasso

        Next thing you know, someone's going to tell me the nose always comes between the eyes!

        Again, Picasso. I think he painted one where the nose was in the armpit.

    • by AmiMoJo ( 196126 )

      I wonder if he was paid to be dumb. Law enforcement loves these numbers. Like DNA and the "one in a billion" bullshit.

  • by Anonymous Coward

    When I worked a temp job at UCSD medical school, several times people said "Hi, Julian!" to me. My name is Mike.

    Then one day, having lunch at the Price Center, I saw a guy who looked a LOT like me. Same profile, hairstyle, goatee, a couple inches taller.

    I walked up to him and said, "are you Julian?" He said yes! I told him people kept mistaking me for him. Asked him what his background was, and he told me biology - I had to explain I meant ethnically. I'm Polish-German, but he was from an Irish family.


  • by nitehawk214 ( 222219 ) on Saturday July 16, 2016 @12:21AM (#52522771)

    My mom always told me "Son, you are one in a million."

    At the current population rate, there are 7000 of me.

    Be afraid.

  • I am often mistaken for an Italian Dwayne Johnson.

  • by haruchai ( 17472 ) on Saturday July 16, 2016 @01:05AM (#52522881)

    From approx 1984 - 1995, I worked in various hotels & restaurants in a big city and I lost count of the number of people who mistook me for another guy who also worked in the biz - one person came right up to me, shook my hand and said it was great to see me again and how he'd enjoyed working with me for several years.

    I had no idea who the hell he was or who he thought I was. But after that, I started being much nicer to people because my double seemed to have left a really positive impression on people in a rough & competitive business so I thought he was doing me a favor and I should at least try to return it.

    Since I left that city and got out of hospitality, it's never happened again.

  • I have systematically elimintated them all over the years.
  • by 93 Escort Wagon ( 326346 ) on Saturday July 16, 2016 @01:44AM (#52522971)

    "Folk wisdom has it that everyone has a doppelganger; somewhere out there there's a perfect duplicate of you, with your mother's eyes, your father's nose and that annoying mole you've always meant to have removed."

    Whose "folk wisdom" is that supposedly referring to? Because I've never even heard this ludicrous notion mentioned anywhere.

    Are "researchers" so hard up for new topics anymore that they're just making crap up and pretending it existed before it sprang from their desperate (and addled) brain?

    • I've heard of this concept many times. Usually it's stated as "Somewhere in the word, there is someone who looks exactly like you [google.com]". If you haven't seen this theory stated before, you probably don't read much, and/or your life experiences are limited.
      • You might want to actually take a look at some of those items. It's all rather recent, and they all seem to trace back to a project by a photographer named Francois Brunelle from about a decade ago.

        "Internet Meme" is not the same thing as "Folk Wisdom".

        • The word "doppelganger" and its concept have Germanic origins from the 1700s. You may want to start reading literature and newspapers in addition to just websites and road signs.
  • by Just Some Guy ( 3352 ) <kirk+slashdot@strauser.com> on Saturday July 16, 2016 @02:04AM (#52523003) Homepage Journal

    When I was in my 20s, I was in a fast food restaurant across town from my house. Some guys started calling out a name I forget. Let's say, Mike. I eventually started looking to see who they were calling to, and was very surprised to find out it was me. The conversation from there was very surreal.

    Me: Uh, sorry. I'm not Mike.
    Them: LOL. What's up, man! We haven't seen you in ages.
    Me: I don't think I know you.
    Them: LOL. Seriously, where've you been?
    Me: Uh, no, really, I don't know you. Who's Mike?
    One of them, as confused as me: What are you talking about?
    Me: I'm not Mike.
    The guy: You're serious?

    I pull out my driver's license, cover up most of it with my thumb, and show him my name. The guy mildly freaks out.

    Guy: Whoa, this isn't Mike!

    They all rush over to look, then stare at me like they're seeing a ghost.

    Guy: We've gone to school with Mike since elementary. I swear to God you look like him. Do you have a twin?

    It turns out their buddy was a year or two younger or older than me. I don't have a twin - I'm absolutely certain about that - but there's someone out there approximately my age that looks similar enough to me that his childhood friends couldn't tell the difference between us.

    • by thegarbz ( 1787294 ) on Saturday July 16, 2016 @03:32AM (#52523177)

      I had a friend who found her doppelganger. She constantly had people mistake her for someone else especially when she was travelling down south. Anyway enter the age of Facebook and one days she was tagged in a photo she didn't have any part in. Sure enough it looked exactly like her. So she did a bit of friending and a bit of connecting and found her way back to the impostor.

      Well turns out she had a twin sister who was adopted away at birth who grew up in a city 200km south of where she lived. Parents had some explaining to do.

    • Another case, just yesterday.

      Saw a guy who looks exactly like a distant cousin of mine, just younger (no grey hair) and a little balder.

      I knew it could not be him, since that cousin lives in a third country, and would not be here without telling me. So, I walked up to the doppelganger, and ask him which country he is from. He turned out to be from a distant country altogether. Told him that he looks like my cousin from a different country than him ...

      But the resemblance is far too weird ...

  • And even though I know how very far apart we are
    It helps to think we might be clicking the same bait.

  • Apparently even identical twins, maybe even identical twin babies, would fail this test. I'm so glad there's nobody out there who could fool a guy I've know literally since we were infants into walking right up to the wrong person before realizing he'd made a mistake.

    I suspect they're unaware that actual humans (and probably most animals) don't necessarily use the same criteria to judge whether somebody is familiar to them.

  • Bizarrely, mine used to work for the same company but in a different country. I never met him, but it was a bit of a surprise for some people from my branch when they visited his office.

  • by BlackPignouf ( 1017012 ) on Saturday July 16, 2016 @03:49AM (#52523231)

    I have face blindness, you insensitive clod!
    To me, everybody is a doppelgänger of everybody.

    • I recognise faces, but I don't connect them to names very well, nor to why I know them.

      People say hello to me, and I say hello back so as not to be rude, then about five minutes later it dawns on me who they are.

  • This is founded on a false premise: that these eight measurements must be identical for humans to look alike. This is false. I have seen people who look alike, it's weird. Moreover I don't think any of them have identical spaces between eyes, etc.

    What I don't get is how educated scientists can come up with such wrongheaded premises to start with. These people are smart, how do they keep on doing this? What happened to the Republic of Rationalia?

    • by swb ( 14022 )

      There was an episode of "Hollywood Squares" back in the 1970s where they brought in actors who looked just like famous people -- I remember one was a dead ringer for Jimmy Carter. I also seem to remember reading about a Hollywood talent agency that specialized in lookalike actors.

      Given humans ability (or willingness) to see faces in the moon, Jesus in a cream pie, etc, my guess is that humans have a recognition system that is very pliant and sees many faces as identical even if they aren't hard-number iden

  • by Anonymous Coward

    > with 7.4 billion people on the planet, that's only a one in 135 chance that there's a single pair of doppelgangers.

    *cough* twins *cough*

  • There is no choice between us,
    If you had ever seen us,
    You'd rejoice in your uniqueness
    and consider every weakness something special of your own
    Being a clone, I have no flaws to identify
    Even this doggerel that pours from my pen,
    has just been written by another twenty telepathic men

  • The world isn't big enough for more than one perfect human!
  • Indeed I do.

    Defence rests, M'lud.

  • He has the same name as me.
    And yes, he's *very* close to me that his friends confused me for him, and vice versa.

  • The chances of anyone in particular having a doppleganger may or may not be one in 137, depending on how you define it, but the chance of there being dopplegangers is about 100%.

    To oversimplify a bit, there could be millions of them in fact, because there's billions of people, and EACH of them have a 1 in 137 chance of having a doppleganger.


    https://en.wikipedia.org/wiki/... [wikipedia.org]

    So it doesn't sound like their software is very good.

  • Straight to it then. The similarity measure this researcher used has not been shown to be what humans use when they, for instance, falsely identify someone in court or mistake two people on clear video.

    The similarity measure she used is designed to detect the differences between very specific and quantifiable points on the human face (interpupilary distance for instance). These landmarks are (largely) immutable over time and anyway amenable to analysis by computers scanning hi-res images.

    However, these quan

  • Since the incidence of identical (monozygotic) twins is a lot higher than that (about 3 per 1000 births)(for fraternal twins it's even higher), there's a math error someplace. Possibly in the assumptions.

    The bad news for law enforcement is that not only will identical twins match on facial recognition (barring some environmentally caused disfigurement, eg scars), they'll also match on DNA evidence. (They won't, however, match on fingerprints.)

  • Of course, Russian Federation is building a bomber. It can't manufacture cars, planes and despite its vast territory is forced to import food. But they are building technology more advanced than all industrialized countries can manage to, at this moment. I am guessing it's going to be manned by volunteers from RF who occupied Crimea. Didn't they say they were going to mars within 5 years at some point in the previous year? This is just another attempt at distraction or attention grabbing when the world
  • Once, in Tucson, as I was walking across a street, a car sped up to me and just bearly stopped short of hitting me. The car contained 3 black girls laughing at how they had scared me. (I should note that in Tucson, the weather is good enough for all the windows to be open.) Then the driver realized that they had misidentified me. "Oh, you're not John," she announced. She then quickly apologized and drove off.

    I'm white. I never figured out who this "John" was.

  • The article is concerned with lookalikes. That's interesting, but what about other kinds of similar people.

    There's a concept that there is someone like you in China who has the same kind of living situation, same kind of job, same kind of lover, and so on. These are more interesting.

  • Given my experiences, I assume that it's a lot more common than people think. I have never seen anybody who looks exactly like me, but years ago when I was at university, I thought I saw my sister walking past me wearing brightly-coloured clothing that she would never wear. I realised that it was not her, and other people thought my sister had gone to another school that she had never attended. I have discovered that the family of a girl that I went to school with seems to have an amazing amount of coinci

  • by Anonymous Coward

    I found out I had a doppleganger 20 years ago. Never met him, despite the fact that we lived in the same neighborhood – just ran into a lot of people who thought I was him.

    Almost cost me a relationship, too. The woman I was dating at the time was out with friends on a Friday night and saw my doppleganger having dinner with another woman. She immediately called me up to bitch me out. Even though I was at home when she called, it took forever for me to convince her that it wasn’t me.

    But, the crazi

  • A living doppelgänger? Nope, I don't have one of those.
  • I actually met the guy. He looks exactly like me and has a tall lean build just like me as well. Here's the story best as i can type it. This absolutely true but no one really believes me so i don't tell it anymore to avoid the 'yep, you've finally gone nutzo looks'.

    In the early '90s i moved up to Toronto, where after work i would often go to a well known local bar. It was a bit of a rough one, no real problems tho with cheap beer and good country music. Some months later a girl i had never met before comes

I've finally learned what "upward compatible" means. It means we get to keep all our old mistakes. -- Dennie van Tassel