Couples usually wait until six to eight dates before they are willing to enter into an exclusive relationship. Speed dating, invented by a rabbi from Los Angeles in 1999, is based on a Jewish tradition of chaperoned gatherings of young Jewish singles. The most common time for breakups is around three to five months. One in three teenagers have experienced violence in a dating relationship. In a survey conducted by MSNBC.com and Elle magazine, more than 31% of men said they dumped an overweight partner compared to 12% of women.