I would think that often it is not necessarily a sense of taste as much as it is a result of environment. Nature versus nurture, if you will. It has been my experience that most of my students eat just about exactly what their parents eat. While that is understandable (comfort in the familiar), it is contrary to the "younger generation being more adventurous" that we hear.
Often, I find there is trepidation prior to trying something new until a student steps up and is the first to partake. And once it is deemed 'acceptable,' others will follow. It is not even just with a particular food, per se, it could be with a preparation. The degree of doneness of red meat comes to mind. Beef can be cooked until it is quite leather-like, but that is acceptable. Until such time that a consumer (in this case a student) tries a different degree of doneness, the familiar style is the only acceptable flavor.
I would also think there is complexity, to a varying degree, in experience. Specifically, I was 14 when I first tried brie. And I liked it! I have done tastings with my students with different cheeses and few have taken a liking to anything more than the familiar specimens from the supermarket deli. The difference between my student and myself? I grew up surrounded by dinner parties, social 'events' and the like. Not many of students have had these experiences to build there palette to relish these flavors. Once they are exposed, time and time again, to varying degrees of complex flavors, they too will have a desire to expand their sense of flavor by trying different food items.
Hope this helps. My bio can be found here:http://www.cheftalk.com/content/bio.cfm?authorid=5