The phrase "generational thing" refers to something that is specific or unique to a particular generation's experiences, values, or interests. Full definition
It's a purely generational thing; when the characters are having the same major life experiences as most people your age, it makes them easy to relate to. (blog.bullz-eye.com)
I don't think it's a generational thing from a behavioral standpoint; people our age just happen to talk to people our age more often and openly. (financialsamurai.com)