Apparently height hasn't changed much since the dawn of man, but it has increased significantly (about 10cm!) in the past 150 years, due to better nutrition, but it's levelling off. It may thus be said that height is not seen as a genetic advantage in itself , but as a signal of better nutrition (although a few centuries is a short time for such a preference to be genetically selected for)

http://www.scientificamerican.com/article.cfm?id=why-are-we-...