According to a study released Tuesday by the National Institute of Emotional Studies, laughter, long employed as a cathartic response to absurd or humorous stimuli, is now used solely to conceal contempt and fear from fellow human beings. 'The original purpose of laughter, to express joy and delight, began waning in the 1960s with the advent of TV laugh tracks, which replaced humans in the task of laughing at jokes,' the report stated. 'Today, 50 percent of all laughter is used as sarcastic mockery of failed attempts at humor, with the remaining 50 percent used to create the illusion of comfort in situations involving tension or deceit.' The report follows a groundbreaking May 1998 study by the institute which found that crying may eventually evolve into a tool used solely for the manipulation of other people. 