The study, as noted by the BBC, says Rom Coms promote unrealistic expectations in their viewers. The research behind this conclusion involved "100 student volunteers [who] were asked to watch the 2001 romantic comedy Serendipity, while a further 100 watched a David Lynch drama." First off, 200 students is a pretty small sample, and secondly, a David Lynch drama will seriously fuck with your head. It's not just a regular non-rom-com. It's usually a twisted, terrifying ride through the deepest recesses of the psyche and the soul.
One of the researchers who worked on the study tells the BBC, "The problem is that while most of us know that the idea of a perfect relationship is unrealistic, some of us are still more influenced by media portrayals than we realize." I'm sure that's true to an extent, but what's telling is that the research participants were all college students. Usually people grow out of expecting their love lives to mimic a Julia Roberts movie by age 24 or so. Or they eventually buy Disney Princess wedding dresses.