Jo-Anne Bachorowski, assistant professor of psychology, Maria Smoski, and Michael J. Owren, professor of Cornell University, found that humans have varied laughter. Not only that, a study conducted on 120 students Vanderbilt University, is known, it sounds laughter can attract people's attention. If we can cultivate it, the laughter can cause a sense of love. "Obviously, the sound of laughter depends on the sex. But the appeal is largely determined by the situation and condition of the person and the environment - including who he is invited to laugh, "Bachorowski explained.