When it comes to human behavior, I have a tendency to look for biological explanations, i.e. it's in our genes. Not that I discount cultural explanations, but they just seem weaker in my eyes. I suppose that shouldn't be a surprise...I am a biologist and I like to think most traits evolved to serve some kind of purpose. Anyways, in the nature vs. nuture continuum, I would suppose that something like color preference would lie on the nuture end of things. I mean, why would someone's favorite color be innate? Well, here is an interesting piece of research that shows that females have a clear preference for red/pink, yet males and females do not differ in their preference for blue. The study was conducted using adults, so genetic and environmental influences are indistinguishable; they need to do a similar study using infants to show that the preference is innate. Nonetheless, I find it fascinating that pink may be inherently more attractive to females, which would just further demonstrate the extent that our biology unconsciously affects our decisions. Makes me almost feel a bit guilty that I bought a pink shirt awhile ago.