Medicinal mirth gets research rebuke

The belief that laughing and humor promote physical health is widespread. A growing movement among health-care workers touts “therapeutic humor” through seminars, workshops, videotapes, and Web sites. However, results of research on the purported health benefits of mirth call to mind a well-told joke with a punch line that falls flat. Or so concludes psychologist Rod A. Martin of the University of Western Ontario in London, Ontario.