It's regional. I spent a few months in southern Spain last year. Here's a representative anecdote: Mixed group of fifteen people in their 30's out to a slow lunch on a Sunday. No one looks at their phone for an hour. Then I catch one woman peek at her phone under the table. After a few seconds her friend taps her arm and she puts the phone away for the remainder of the gathering.

My theory: American culture is individualistic and not heavily tradition based. This allows new tech, habits, rituals, and patterns of living to catch on quickly. This is both a good and a bad thing.