The rea­son that I am inter­est­ed in behav­ioral con­ta­gions is that I firm­ly believe that if we can under­stand how behav­iors spread in a social net­work and thus in a pop­u­la­tion from per­son to per­son to per­son to per­son, that we could poten­tial­ly pro­mote behav­iors like…condom use, or tol­er­ance.