But I have to say a lot of it is probably cultural (perhaps genetic to some extent as well) and that from what I've seen the guy in that folk song is the one in the minority, at least in most of the West. For every Van Morrison going on about his brown eyed girl there's a dozen others going nuts for "beautiful baby blues". Preferred color is really a separate issue than the attractiveness of the eyes themselves though; not only do the shape, distance etc. play a role, but someone who likes brown eyes might find one shade very appealing and another very bland, for example, and a person with two different colored eyes can be strongly attractive to some people yet strongly unattractive to others.