Why are we afraid?

Fear is the natural response to threatening or dangerous situations, but what is it that causes us to experience it?

It is, perhaps, the most primitive human emotion of all . In fact, not experiencing it would be a death sentence for any animal on earth. Fear is a natural and inevitable reaction of our body to situations that are, either instinctively or rationally, threatening.

Increased heart pressure, muscle contraction, dilation of the pupils, sweating, drop in body temperature … We all feel fear more or less frequently. Being scared of something does not mean that we are more or less “tough”. In fact, the person who experiences the most fear is surely the most evolutionarily gifted person.

What is fear exactly?

Fear is a primary emotion that all animals experience and that consists of experiencing unpleasant sensations in the body as a result of exposure to danger.

This danger can be real or imagined and present or future. Thus, humans are afraid of many things: death, a break, an animal, the dark, loneliness, pain …

Therefore, there are countless circumstances that can ignite that “spark” necessary for us to begin to feel fear. Although there are some more frequent than others, the truth is that each person is afraid of different things.

However, the explanation for why we experience this unpleasant situation is common to most fears and we must understand both our genetic endowment and the biochemical mechanisms of our body.

In this article we will take a tour of the science behind fear and we will try to analyze why the body makes us experience this sensation and what processes occur within us that lead us to be scared.

What is the evolutionary meaning of being afraid?

It may seem that fear is an exclusive emotion of humans since we are able to process what surrounds us in a more conscious way, which makes us understand the consequences that different situations can bring and, therefore, be afraid of them.

But the truth is that fear is one of the most primitive and strongest emotions in nature . All animals, although it is true that perhaps for reasons other than us, experience fear.

In nature, animals compete to survive. It is a constant battle between eating or being eaten. For this reason, over millions of years of evolution, the nervous system of animals developed a mechanism that allowed organisms to act very quickly in the face of life-threatening stimuli.

  • To understand how evolution works: “Charles Darwin: biography and summary of his contributions to science”

The faster animals responded to threats, the faster they would escape danger and thus survive longer. Thus, evolution rewarded animals that acted most effectively in the face of hazards.

This answer is fear. Fear is our body’s way of warning us that we must flee . And this is applicable both to what happens in the African savannah and in the streets of our city.

Fear is what allows animals to quickly escape their predators. When animals see danger approaching, the brain gives the warning signal and makes it flee as soon as possible.

It is for this reason that we say that fear is the most primitive emotion that exists, since it is the survival mechanism par excellence. Without fear, it is impossible for animals to survive in a world full of dangers.

In the case of humans, what makes us fear?

Obviously, no lion is going to try to devour us while we walk down the street. However, humans experience fear just like other animals. Even more, precisely because we have conscience and we anticipate events.

Thus, people are afraid when we are faced with a real danger, such as being robbed in the street. However, we also feel fear when we analyze a situation and relate it to an event that can pose a threat , such as hearing noises at home at night.

We can also be afraid simply of tricks that our mind plays on us, for example when imagining that a relative of ours may suffer a serious illness. We are also afraid of all the things we cannot fight against, such as death.

Anyway, we are not only afraid as a result of the rational interpretation of what happens around us. Many studies have addressed the analysis of the deepest fears that humans have and that have little to do with intelligence.

Why are spiders and snakes generally scary? If we analyze it rationally, the vast majority (if not all) of the spiders that we deal with in our daily lives are not much more dangerous than a fly. And in the case of snakes, we fear something that is practically impossible for us to run into throughout our lives.

To understand this you have to go back to the past. Thousands of years ago, our ancestors lived in the middle of nature or in caves, places where animals such as spiders did pose a threat, as some of the species were deadly. Even if we go back to the apes, snakes were one of the biggest threats as they acted as predators.

This adversity to these and other creatures is so profound as it goes back thousands of generations. The fear of some animals is practically inscribed in our genes, and that is why we have many innate fears. Our genetics tell us what to fear .

In short, humans feel fear innately or acquired through lived experiences and the way of being of each person. Therefore, there are countless situations that we assimilate as a danger and, consequently, our body responds so that we get away from it.

What happens in our body to trigger fear?

Fear is a biochemical response to a real or imagined danger. In general terms, the brain interprets what is happening around us and if it sees something that may pose a risk to the body, it triggers a cascade of chemical phenomena that makes us experience fear, an emotion that has the objective of making us act effectively before the threat to combat or avoid it.

But what is the process by which our body goes from calm to being scared? Next we will review what happens to our body when we feel fear.

  1. Perception of danger

Let’s imagine that we are walking down the mountain. Everything is calm, so our brain is calm and, consequently, we feel relaxed. But suddenly, in the middle of the road we see a wild boar.

At that moment, our brain perceives a situation through sight that, after analyzing it, comes to the conclusion that it is a danger . We have to avoid that danger, so it sets off the chain reaction of fear.

  1. Activation of the brain amygdala

The amygdala is a structure of the brain whose main function is to link emotions with the necessary responses.

When we have perceived a danger, the brain amygdala is activated and, depending on the signals it has received, it will send one information or another to the rest of the nervous system. If the amygdala interprets this as a danger, it will make the whole body realize that there is a threat to face.

The amygdala is the control center of primitive emotions and, therefore, it is it that determines when to experience fear and when we can be calm.

When the amygdala receives the news that we have encountered a wild boar in the middle of the road, it will warn the rest of the body that we must act immediately. And the way that the different organs of the body communicate is through hormones, which are biochemical messengers.

Once activated, therefore, the amygdala orders certain hormones to begin to be produced: adrenaline, norepinephrine, antidiuretic hormone, endorphin, dopamine … All these molecules will circulate through our body and reach their target organs, at which point we will begin to notice that we are afraid.

  1. Experiencing unpleasant sensations

Fear is an unpleasant experience precisely because it is designed to be so. Hormones released by order of the amygdala travel through our body and convey the message that we are in danger. In this case, a wild boar.

The reactions caused by the hormones mentioned above are many:

  • Pulmonary function (we breathe faster to oxygenate more) and cardiac function (the heart beats faster to pump more blood) is accelerated
  • Stomach function is inhibited (that’s why we notice dry mouth)
  • Pupils dilate (to improve vision)
  • Increases muscle tension (in case you have to run)
  • Brain activity increases (we may feel paralyzed, but our brain is working very fast)
  • The immune system stops (only energy goes to the muscles)
  • Sweating is increased (to refresh the body in case of having to flee)
  • Blood flows to the major muscles (this is why it is normal to look pale on the face)

All these physiological reactions are designed so that we can more efficiently flee from danger . That our pulse races, that we sweat, that we turn pale or that our mouth becomes dry does not mean that we are scary. It means that our body works correctly and that, when faced with danger, it makes us feel afraid.

Fear, therefore, is an emotion that triggers the production of hormones that will travel through our body and that will alter our physiology, giving rise to symptoms that are an indication that we are ready to flee from the threat.


by Abdullah Sam
I’m a teacher, researcher and writer. I write about study subjects to improve the learning of college and university students. I write top Quality study notes Mostly, Tech, Games, Education, And Solutions/Tips and Tricks. I am a person who helps students to acquire knowledge, competence or virtue.

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