How do animals smell fear in humans

You can smell fear!

In keeping with Halloween, we want to dedicate this post to the topic of fear. If you don't have anything sweet at home and therefore have to fear sour things, you can start to sweat from fear. And you can smell this fear! We know when we scare someone or watch horror films that you can watch someone's fear because it is literally written on their face. Often the expression of fear is accompanied acoustically by a screeching or loud scream, which makes the whole thing even clearer. But our sense of smell can also perceive fear, even if only unconsciously. We took a closer look at this topic ...

Danger! Risk of contagion!

Many have probably heard that dogs can smell fear. A large dog turns the corner and when it barks or bares its teeth, we emit signals of fear through our sweat, which the four-legged friend can smell. Aside from that, dogs can sense many other emotions through their noses and supposedly even smell cancer.

Depending on the breed, these four-legged friends have an average of 125 to 220 million olfactory cells, whereas we only have around five million. But the fact is that this “small number” of olfactory cells is also sufficient to perceive fear through the nose. However, this happens unconsciously. If someone smells like fear, this automatically triggers an alert! So we are infected with the fear of the other!

If we were to specifically train our nose, we could classify the state of mind of our counterpart based on their body odor. Not to the extent that dogs or other animals can do this, but at least more purposefully ...

Fear sweat, what's inside?

On a conscious level, most people cannot perceive any difference between fear sweat and, for example, the sweat in the course of sporting activities. As already mentioned, this happens unconsciously and can influence our behavior.

The biochemical processes involved in this so-called chemical communication have not yet been clarified. As messenger substances, for example, pheromones (fragrances that have a specific effect on living beings of the same species) or a mix of different smells that arise from the breakdown of stress messenger substances. When we are afraid, our body reacts with increased blood pressure, proteins, fatty acids, urea and cholesterol are released and the bacteria on our skin do the rest by interacting with the sweat, creating breakdown products and providing the typical smell. For example, butyric acid is created through the breakdown of long-chain fatty acids, which causes an unpleasant odor ...

Research has shown that the smell of fear activates centers of emotion in our brain. For this purpose, the brain activities of test subjects were examined in a magnetic resonance imaging (MRI) scanner while they smelled odor samples from students who were about to take an important test. The smell of sports sweat as a cross-check did not lead to any clearly measurable activity in the brain.

Did you know that our sense of smell also plays a role when choosing a partner and eating?

The nose plays a key role in our sense of taste. For example, if we have a cold or happen to be on a space mission (see article: Life in weightlessness - visually young, physically problematic!) Our nose swells up and our food somehow tastes pretty bland ...

In addition, the expression “being able to smell good” is not used by the hair, because those who can smell good also go well together! We can tell through our nose whether the genetic makeup of our counterpart matches ours and how strong their immune system is. After all, our offspring should only get the best genetic material on the way in order to be able to ward off diseases optimally and to ensure the existence of our species. So, "nose on" when choosing a partner!

More about the perception of smells and our sense of smell to try out in class can be found here:
https://www.phywe.de/de/unser-geruchssinn.html

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