Quote from Barney in Not a Father's Day
Marshall: Barney, they're hot.
Barney: Oh, there is so much to teach you all. You have just become victims of... The Cheerleader Effect. Glad you asked. The Cheerleader Effect is when a group of women seems hot, but only, as a group. Just like with cheerleaders. They seem hot, but take each one of them individually? Sled dogs.
Ted: That's insane.
Barney: Take a good, hard look at each one of those girls. Individually.
Marshall: I don't know. The one on the end is kind of cute.
Lily: Yeah, she really is.
Barney: Also known as the Bridesmaid Paradox, Sorority Girl Syndrome, and for a brief window in the mid-'90s, the Spice Girls Conspiracy. Scary Spice indeed.