A study conducted by scientists in the Czech Republic revealed that the dog has the ability to distinguish people who are identical twins. The results of this study could change the way people train dogs to recognize people that have been done by recognizing the smell.
In the experiments they do, the researchers tried the dog to distinguish the two sets of identical twins, two boys aged 5 years and two daughters aged 7 years. Researchers have also tried using the two fraternal twin girls aged 8 years and 13 years old male. Fraternal twins are the same but the children born from two eggs fertilized by two different sperm cells.
Experiments carried out with 10 dogs, german shepherd and each dog was tested by performing 12 tests. All dogs are asked to smell an odor sniffer and look the same from 7 possibilities. From experiments, researchers found that all the dogs chose the right answer.
Dogs are able to distinguish a child from its twin without once making a mistake. Dogs can still guess despite all the twins lived in the same place and eat the same food with their twin.
For comparison, DNA tests can not distinguish between identical twins even though DNA tests are still able to distinguish between fraternal twins who only have a gene similar to its twin. Apparently the dog is a very special thing, especially if the dog is trained. About how a dog can distinguish between identical twins, researchers acknowledge the possibility of external factors such as infections that can affect every body odors of twins.