I've noticed on some of my recent flights an interesting trend--it seems that what appear to be the older FAs tend to be working in Y while the younger FAs work F which usually means the F passengers get the FA that was hired more recently.

Perhaps AS Flyer could easily answer this, but how do the FAs determine who is going to work in which cabin? Do they get to decide among themselves when they show up for the flight? Is it based on seniority (as it would seem)?