Police dogs have been very useful in identifying criminals. However, it has been noticed that they might find it difficult to trace some people. Well, we now have an explanation of why are dogs unable to identify some people in real life circumstances while they perform exceptionally well in training. Like all the other codes of life, the answer is in our genes!

A geneticist, Francesco Sessa reported in the annual meeting of the American Academy of Forensic Sciences that dog might not be able to find people with a specific version of a gene named SLC6A4. This gene has been studied and worked on before as well with respect to the issue of stress management.

Their findings explained that when a person is in stress, their body odor changes if they have a shorter version of this gene (SLC6A4). People with longer version do not exhibit this change and so dogs can easily identify them even if they are in stress. The experiment that they conducted included four volunteers; one man and woman of both long and short versions of this gene. Having a sample of their normal scent through a scarf, the researchers then asked the volunteers to go in the lab and the first session was conducted without any stress-inducing activity. The dogs sniffed the scarves and were easily able to identify all the volunteers. However, after the second session which included a stressful activity of public speaking and the researchers made sure that the participants are stressed out, the dogs were sent again. This time, they were only able to identify the volunteers with the longer version of SLC6A4, as their body odor didn’t change.

The experiment clearly showed how people who tend to have a shorter version of this gene experience a change in their original body odor. While this is an important finding, it is necessary to keep in mind that there might be other factors involved in the process which are still unexplored and being worked upon. This in no ways means that police dogs are now useless. Not only are they able to identify people with a longer version of SLC6A4, but are also beneficial in situations when the person missing is with a relative or acquaintance that they are not afraid of.