Then comes the choice to send a person a message, or to reply to one.
Bruch's team devised a statistical model that maps the "decision rules" people follow during the first two steps.
Bruch and her team divided the rules into two broad categories, "deal breakers" and "deal makers," used to exclude or include people for the next level of contact.
About 45% of couples met on dating sites; the rest met on online social networks, chat rooms, instant messaging or other online forums.
Lead author John Cacioppo, a psychologist and director of the Center for Cognitive and Social Neuroscience at the University of Chicago, says dating sites may "attract people who are serious about getting married."While Cacioppo is a noted researcher and the study is in a prestigious scientific journal, it is not without controversy.
Not according to a study of more than 1 million interactions on a dating website published this week in the .