The Palos Heights–raised art photographer Richard Renaldi has spent the past six years cozying up to strangers. “I was always curious in how different people relate to each other in a group,” says the 45-year-old New York University alum, who approaches his subjects at street corners and public landmarks and asks them to pose in overly familiar positions. “I probably get about a 40 percent rejection rate.”

But he still managed to snap the 73 photos that appear in Touching Strangers (Aperture, $30), out this month. For the stories behind those he took in Chicago, see below.