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Dogs Can Sniff Out the Differences Between Identical Twins

Twins chow down at the Mule Skinner Saloon in Oxford; photo by Joel Sartore


Who is who in this picture?  Maybe you can’t tell the difference but your canine friend, Rover, might be able to help you out.  According to recent study conducted by scientists in the Czech Republic, some dogs are able to distinguish between identical twins even when a DNA test cannot.  Dogs in the experiment sniffed samples from sets of both identical and fraternal twins between the ages of 5 and 13 years old.  Samples from unrelated children were included as well.  In every trial, researchers found that the dogs could both match the twins’ scents and distinguish them from one another — indicating that even people with identical genes have their own unique scent.

Rover might need a little practice before performing this trick, however.  All the dogs used in the experiment were German Shepherds and highly trained.

The scientists have published the results of their study online in the journal PLos ONE.

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  1. Me
    March 12, 11:06 am

    Its not about what aftershave you wear or what you had for lunch. Dogs can smell internal disease. They can detect brain tumors. Their sense of smell goes deeper than skin level. Plus they can detect subtle changes in energy. Humans beings are electrochemical machines.when a DNA telld can’t detect these differences but a dog can, you have to look at the notion that its more than just smell.

  2. James Smith
    João Pessoa, Brazil
    July 24, 2011, 6:37 pm

    The test is very unscientific. Differences in scent can be from many factors, diet, aftershave, degree of physical activity, type of clothes worn, aftershave, soap, other people in their normal proximity, many other factors.

    Until all variables are eliminated, this “experiment” means nothing.

  3. […] Dogs Can Sniff Out the Differences Between Identical Twins Twins chow down at the Mule Skinner Saloon in Oxford; photo by Joel Sartore […]

  4. Red Twin
    July 11, 2011, 8:53 pm

    Guess what? Anyone can tell the difference if they actually know the twins. My husband can hardly see the similarities between me and my identical twin.

  5. Shab
    July 11, 2011, 12:22 am

    Are you kidding? DNA test cannot?
    That is amazing that dogs can do that, but who says that DNA test cannot distinguish such a simple difference!

  6. Arbie
    July 10, 2011, 2:28 pm

    I wonder…. has there been any case where a wife mistakenly took his bro-in law for her hubby ? If its ‘done’….wow….thats serious !

  7. Stephanie
    July 10, 2011, 1:39 pm

    Not really a surprise, people all have their own scents, regardless of how much we cover it up with deodorant and perfume. It’s not an awful one, but you know how certain houses smell different and girls keep boyfriends’ sweaters because they smell like them? Same thing, it isn’t surprising that two people have different smells, regardless of genetic makeup.

  8. Saqib Khan
    July 10, 2011, 1:34 pm

    Even dogs are able to detect cancer long before it is confirmed by a laboratory. I read long time ago that a dog kept on licking a particular part on his master’s leg that made him curious and consulted his doctor. They found out through blood test that he was suffering from early stages of Melanoma.

  9. Beverley Sutton
    July 10, 2011, 1:15 pm

    @Warren … the photograph above is merely an illustration showing identical twins … and has nothing at all to do with the experiment which the article reports was done in the Czech Republic and not at “at the Mule Skinner Saloon in Oxford.”

    I haven’t read the study, but one assumes that the researchers corrected for obvious scent differences such as those caused by diet, personal and laundry soaps … or they would not have been published.

  10. Abhishek kumar
    nioda india
    July 10, 2011, 1:03 pm

    Did they try the same experiment with younger children? If so, How young?

  11. Abhishek kumar
    nioda india
    July 10, 2011, 1:01 pm

    i love food

  12. Daphne Gagnon
    Montreal, Canada
    July 10, 2011, 1:00 pm

    I have a blind dog and I am an Identical Twin. When both my sister and I walk into my appartement my dog sniffs my sister and waggs her tail, then she sniffs me and goes nuts, jumping and vocalizing. So yes she can tell differences between us

  13. Susan Pierce
    Wilson, NC
    July 8, 2011, 9:02 am

    Did they try the same experiment with younger children? If so, How young?

  14. Warren Levine
    United States
    July 8, 2011, 12:54 am

    LOL! Obviously, if the one on the left has a burger with his mountain of waffle-fries, he’s gonna smell different than the one on the right who’s eating a fish sandwich with his (slightly larger) mountain of waffle-fries

  15. samgoldencoffee
    July 7, 2011, 11:47 pm

    wow….things the four-legged friends can do.
    very amazing.