Why do humans shake hands as a universal form of greeting?

Humans shake hands as a universal form of greeting because it’s like giving each other a friendly high-five but with hands instead of fives.

When two people meet, they often use their hands to show they are friendly and open. A handshake is like saying, “I am not going to hurt you.” It’s like when you say “hi” but with your hands, it feels more real and important.

People from all over the world have different ways of greeting each other, like hugging, kissing, or bowing. But a handshake is simple, just two people putting their hands together and moving them up and down. It’s easy to learn and does not need any special tools or training.

That’s why you see people shaking hands when they meet in many different places, from your school playground to faraway countries, it's like a global high-five!