(1) Smile and you will be young in ten years; worry and your head will turn gray - from "The White-Haired Witch".

(2) Always be happy and laugh often, the way to prolong your life is from the way of health preservation.

(3) When humans think, God will laugh - from the Bible.

Extended information:

Psychologists have now discovered that laughter is one of the oldest ways for humans to communicate with others. Before that, laughter was only seen as a human A sense of humor. Humans laugh to express solidarity with others or to laugh at them, or to use laughter to flirt with others. Each of us mastered this skill long before we learned to speak.

Not just for fun, laughter is an expression. Until now, scientific research has linked laughter and humor. But scientists have discovered that another aspect of laughter is even more important. It has nothing to do with humor. We use laughter but always underestimate its power. By laughing, people convey a message.

Although laughter can be heard by many people, only specific recipients can understand the message contained in the laughter. The message appears to be encrypted because it is directed at the recipient and does not require his conscious understanding.

Baidu Encyclopedia-Laugh