Body language appeared long before people learned to communicate with each other through spoken and written language. And many of the nonverbal cues we use every day are truly ancient—they helped our ancestors, for example, find food and make useful connections.

Ph.D. and psychologist Ronald Riggio explains how the body’s five most common signals may have come about.

1. Raised eyebrows.

Imagine that you are walking down the street and suddenly see a familiar person. You are unlikely to realize it, but your first reaction will be raised eyebrows – they mean that you recognize your friend or friend. Scientists are confident that this form of greeting originated a long time ago – it later evolved into shaking the head when meeting someone.

2. Handshake.

The handshake also appeared quite a long time ago; its history goes back to our warlike ancestors. When a person extended his hand, it meant that he did not have a weapon and that he had come for peaceful purposes. His counterpart also had to show his palm. Eventually people started shaking hands.

By the way, in the Roman Empire, a handshake began to symbolize friendship or loyalty.

3. Outstretched hand.

The oldest gesture is considered to be an outstretched hand – this is how a person asked another to share food. The pleading gesture, which demonstrates defenselessness and weaponlessness at the same time, is now often observed by zoologists in chimpanzees.

4. Dilated pupils.

It is common knowledge that when we look at a person we like, our pupils dilate. Scientists say that women with wide pupils are perceived as more attractive – and it seems that our ancestors knew this too.

Thus, during the Renaissance, women put drops of belladonna into their eyes to attract male gazes. Of course, sometimes this led to blindness – but what can’t you do in order to get married successfully?

Why people needed kisses is still not entirely clear. On the one hand, the exchange of saliva contributed to the spread of dangerous diseases. On the other hand, our primitive ancestors may have used kissing to assess the health of a potential partner. In any case, kissing from the very beginning meant a desire to have sex. However, if people kissed each other on the cheek, it was a warm greeting.