Why do humans shake hands as a form of greeting across cultures?

Humans shake hands as a form of greeting because it shows trust and friendship, like when you high-five your best friend after a game.

When two people shake hands, they are showing that they are open to being friends. It's like when you give someone a hug, you're saying, "I like you!" But instead of hugging, you just touch hands. This is simple and easy for everyone to do, no matter how big or small they are.

Shaking hands has been used by many people all over the world because it's a simple action that needs no special tools or training. Just like how you use your hands every day, eating, drawing, playing, shaking hands is something that feels natural to most people. So whether you're in Africa, Asia, Europe, or anywhere else, shaking hands helps people say hello and show they are ready to be friends.