Don't pair up with matching genes 11:30 05 January 2007 NewScientist.com news service Matt Kaplan They say opposites attract – and a couple’s differences may be key to lasting happiness, according to a new genetic study of people in relationships. The findings were so predictive, that a DNA test could one day reveal how likely a woman is to cheat on her partner, the study suggests. Psychologist Christine Garver-Apgar at the University of New Mexico in Albuquerque, US, and colleagues investigated whether genetic similarities among romantically involved couples predicted how faithful and sexually responsive the partners were to one another....