Dogs can sniff out the stress even in strangers, finds study
(Wikimedia Commons/Jurriaan Schulman https://bit.ly/3dR3u7U)
A team of researchers from the British Universities of Belfast and Newcastle found that dogs feel our emotions, focusing not only on sight, but also on the scent.
A study on 36 people and four dogs led by psychologist Clara Wilson showed that pets can detect a person's nervous tension through their sense of smell.
The dogs can also distinguish between the smell of stress and the smell of a calm stranger on the first try.
Over thousands of years of coexistence with us, dogs have learned to interact effectively with us. For example, they can read human emotions and influence them.
We still don’t know the physiological reactions of dogs to whether a happy person is next to them or in a state of stress.
However, if we talk about the perception of emotions, it is not entirely clear what dogs rely on more.
They may well be guided by gestures and facial expressions.
It is also unclear whether the animals need training for this, or whether the perception of human emotions is an innate canine trait.
THE STUDY
Now, Wilson’s team of animal psychologists took 20 domestic dogs who were trained.
They were presented with odor samples (sweat and exhaled breath) of 36 people who were calm or under stress.
To induce stress, the subjects performed complex mathematical mental operations.
This evoked a feeling of tension in the subjects, an increase in blood pressure and pulse rate.
Then the researchers presented the dogs with samples of volunteers' odors.
First, the subjects had to distinguish human odor from two unused sampling kits used as control samples (10 attempts).
Secondly, one of the control samples was replaced with a “calm” smell from another person (20 attempts).
At the third stage, there were two different “calm” samples from a familiar person and a control, and from them it was necessary to choose a previously familiar one.
If the dog completed 70% of the attempts in the first part and 80% in the second and third, then the experimenters admitted the animal to the main part of the experiment.
Of the 20 dogs that were involved in the selection, only four made it to the end.
The experiment itself was arranged according to the same scheme:
- 10 attempts to get acquainted with the sample of the smell of a person in stress and
- 20 attempts to distinguish the smell of stress from the smell of the same person in a calm state.
In total, four dogs completed 720 sweat and breath pattern recognition attempts.
(Wilson et al. / PLosOne, 2022 https://bit.ly/3LV6YCQ)
THE RESULTS
In 93.75% of cases, the dogs guessed the right pattern, which is significantly higher than the probability of random guessing.
In different dogs, the result was from 90% to 96.5%.
If we consider only the first attempt to distinguish a “calm” smell from a “stressful” one, then the proportion of correct answers was 85%-100% (94.44% on average),
This is indistinguishable from the final result.
Thus, the dogs did not require training to distinguish the smell of stress from calm.
Unfortunately, the study did not involve determining the composition of volatile organic compounds that the dogs smelled
So, we still don’t understand which substances the animals focus on in the first place.
Further research will help us better understand how the emotional connection and non-verbal communication between the dog, the owner and strangers works.
It is important to note that only 1 in 5 pets was able to quickly learn to identify the smell of stress in the experiment.
Furthermore, the authors did not explain why the rest of the animals did not pass the selection.
(Clara Wilson from Queen's University Belfast with Leon the dog. Clara Wilson, Queen's University Belfast https://bit.ly/3CkG6cA)
Source:
- PLoS One: journals.plos.org/plosone/article?id=10.1371/journal.pone.0274143
- Eureka Alert: https://www.eurekalert.org/news-releases/965954
- The Guardian: https://www.theguardian.com/science/2022/sep/28/dogs-can-detect-people-stressed-research-odour-profile
If you like my content, please consider following, upvoting and commenting. I really appreciate it.
Follow my Telegram channel: https://t.me/stemsteemit
