There's lots of evidence that people in their early 20s and under are psychologically different than older people (higher rates of anxiety/depression at the same age, etc.). Anecdotally, I've noticed that people don't talk to strangers as much on planes anymore as when I was a child.

I guess you could argue that technology isn't to blame, but technology changes people. And it's hard not to use technology when it's so pervasive. At work I have a hard time not eating donuts when someone brings them in. Technology is similar. If everyone around you is on their phone or facebook or whatever it takes a lot of willpower/willingness to be different to not do the same.