Humor has a great effect on the brain - it makes both hemispheres work. When you perceive a joke, the left brain turns on. When you laugh in response to a joke, the right side also becomes active. There is evidence that people approach problem solving with more creativity if they have warmed up with humor first. Other research confirms that laughter increases creativity and flexibility of thinking. Perhaps a smile is not as healing as laughter, but it also has a beneficial effect on the body. Facial expression and emotional state are connected to each other through the nervous system. And very often a smile is followed by laughter. Laughter and smile not only reflect the inner state. They are able to influence him and set an emotional mood. A smile on your face makes your heart smile.