Why do you feel itch when others scratch?

A new study sheds light on this phenomenon, after discovering that our brain is very concerned about this action.

When you see someone scratching, you may begin to feel itchy due to a "social infection" reaction.

A new study finds that our brains are very concerned about the actions of others instinctively.

Simply put, social spread is "imitation" of behavior or attitudes among individuals.

Yawning is considered a contagious social behavior. When we see others yawn, we tend to react to actions by yawning.

Similarly, itching is also an "infectious" social behavior. According to a team from Washington State University (USA), sometimes just mentioning the word "itch" is enough to make us want to scratch.

Many people think that reflexes exist only in mind, but experiments show that it is instinct and not a form of empathy.

To verify, the team applied a test on mice.

In the experiment, the mice were placed in the room with a computer screen, on which a video of another mouse was scratching. Just a few seconds later, the mice in the room began to scratch.

You may start to feel itchy when someone is scratching because of a "social infection" reaction.

This is surprising because mice have poor visibility. They often use the smell and touch to explore around; so whether the mice see the video is still a mystery.

But even if they don't see the video, they can know exactly the scratching animation of the mouse on the screen.

The results of the mouse's brain activity after watching the video showed that the suprachiasmatic nucleus (SCN ) area of ​​the brain, involved in regulating the sleep cycle, dramatically increased activity.

When analyzing rats' brain activity when they began to scratch, the team found that SCN released a substance called GRP (gastrin-releasing peptide).

In previous reports, science noted GRP was associated with the transmission of "itchy signals" between the brain and spinal cord.

If GRP or brain cell receptors are blocked, the rodents will not react when they see other mice scratching it.

In other words, mice experimented with seeing another mouse scratching itch and thinking that it also needed to do the same. According to the authors, these findings show that the mouse itself cannot control scratching. When seeing similar behavior in other mice.

Instead, the mouse's brain began to produce itchy signals using GRP as a messenger. It is an innate and completely instinctive behavior that humans have the same expression.