Originally Posted by pptp
If by "manipulate" you mean "keep pax safe during potential or known times that it's unsafe to be up" then yes, you are correct.
It's more than just that. American crews seem to take the cake in having the seat belt sign on for the greatest portion of a flight ... even when there is little/no turbulence. And I don't believe that American crews are any more forgetful than non-American crews vis-a-vis the seatbelt sign.
The seatbelt sign during meals is certainly coordinated by at least some AA and DL and NW employees.