Laughter is natural for people. We start to laugh at about four months of age. We start to laugh even ________ we start to speak.

Laughter connects us with others. We laugh more when we are with other people. It’s difficult to pretend to laugh. Laughter is ________. When people pretend to laugh, most people know it’s not real.

When do people laugh?

Only 10 to 20 percent of laughter is about something ________. Most laughter is about being friendly with other people. Most laughter says, “I don’t want to ________ with you. I want to be friendly with you.” This kind of laughter brings people together.

We often laugh when we feel nervous. In movies, there is often a joke at an exciting moment when everyone feels nervous. It is usually a(n) ________ joke, but we laugh a lot. Our laughter helps us ________.

Why doesn’t everyone laugh at the same joke?

Not everyone has the same sense of ________. Some people think a joke is funny, but other people don’t think so. People have different ideas about what is funny.

Our idea of what is funny changes with ________. For young children, the world is new. They are interested in many things, so they laugh ________. Teenagers often laugh to protect themselves. Adults laugh at themselves and other people with similar problems. They laugh at things that give them stress. Our ________ for laughter change gradually.