Between 2005 and 2011, the rate of men who have sex with men (MSM) who reported having anal sex without a condom in the past year increased by 19 percent. In a noteworthy nuance, risky sex in 2011 was dramatically lower among those who accurately knew their HIV status.

Pooling data from ongoing surveys taken in 20 major cities, researchers at the Centers for Disease Control and Prevention (CDC) found that 48 percent of the study participants reported condomless sex in 2005, a figure that rose to 57 percent by 2011. The CDC theorizes that “serosorting” may partly account for the rise: Men choose to have latex-free sex with those whom they perceive as having the same HIV status as themselves.

Perry N. Halkitis, PhD, MPH, a professor of applied psychology, public health and medicine at New York University who researches sexual risk taking among MSM, is dismissive of the popular notion that younger MSM are simply blasé about the risks of sex without a condom. “That's what old gay men say,” he notes.  Reflecting on a generation confronted, for example, by unique economic challenges their forebearers did not have to face, Halkitis adds: “It is clear to me that while young men don't want to get HIV—they're afraid of HIV—it is not their primary problem.”