Everything has changed except human nature.

Your example shows how far cultural norms have shifted. Reading a paper around others is anti social in a culture where you are expected to interact with and give others your attention.

Each generation may react the same way to the new behaviors of the next generation, but that does mean those new behaviors do not form a consistent trend representing real change in the culture. In this case that trend is increasing individualism and weakening of community norms.

A paper generates a lot less dopamine than candy crush