I say, let's blame TV! The theory...<p><a href="http://www.slate.com/id/2151538/" rel="nofollow">http://www.slate.com/id/2151538/</a><p>If true, there are all sorts of chemical, physical, and psychological processes that could be the mechanisms:<p>- less sunlight/vitamin-D<p>- less interactive time with real people, more time with scripted/non-reactive people<p>- less time in nature/3D<p>- less exercise