Pop culture has an extraordinary ability to affect the perceptions of the masses – you view a whole bunch of TV shows about being stupid and self-involved and immature, and this starts to skew your idea of what is normal and acceptable in the real world. Television cannot accurately represent reality, but it still affects how we perceive the world and people around us.
Here's a thing I wrote for Birdee mag on Girls, how boring and white-washed mainstream TV is, and the perpetuation of dangerous stereotypes.