&nbsp; On average, we laugh more than 15 times a day. We make different laughter in different situations. But the reason why we laugh is still unknown for the majority of individuals. Scientists claim that laughter is contagious and has a social function.<div>&nbsp; To begin with, laughter occurs unconsciously. Even we can consciously intervene something, we do not consciously produce laughter. Laughter controlled mechanisms, located a long way away from brain region that develops later and controls higher functions such as language or even memory, explain why laughter is so hard to suppress.</div><div>&nbsp; However, this isn't the accurate answer. There is another factor that it's associated with relationship between people. Laughter is a message that we send to others. An infant, for example, laugh just like he or she cries to interact with the mother or other caregivers. For that reason, laughter has a bounding function with individuals in a group. Additionally, it's not used for positive reasons, there is also a dark side: belittling or showing disdain.</div><div>&nbsp; In a word, we laugh because we would like to do it, because our brain accomplishes it, and because we want to interact with each other socially.</div>