I would also argue that the spread and popularity of "social" networking, and the cliquey nature of American undergraduates (which is the stage in their late te

I would also argue that the spread and popularity of "social" networking, and the cliquey nature of American undergraduates (which is the stage in their late teens) also heavily contributes to this. Over-supervision by parents leads to college students around in a coffee shop working, hooked to their iDevices, staring into their Macbooks while they "like" the last 20 items their "friends" posted on Facebook. They go to the supermarket for most of their needs, but are almost surprised if anyone actually talks to them. They don't get to interact with basically anyone outside of their tiny little group of (real) friends [although they have tons of Facebook ones that provide limited mental satisfaction], and thus are often awkward and lonely when they move away for work. The only solution I can see for this is for parents to a) let their children be outside, unsupervised for longer periods of time, and b) to intensely monitor their online activities at a younger age, and not give them access to smartphones. This will act as a forcing function for simple social skills, like talking to a stranger without going goggle-eyed.