Is vomiting a learned behavior in cats?

[Tiggaroo]

We are at our wit's ends with our three cats. The oldest is 11 and has had the habit of vomiting on occassion since she was young. Oddly enough, despite the occassional cookie tossing, she is rather rolly polly. She's perfectly healthy. We've put her on I*MS weight and hairball control and the symptoms are now much less frequent. But now the other two cats are vomiting as well. Problem is, they are both thin and can't afford to lose weight. We keep the fat cat food on the floor and keep regular I*MS food on a table, which the fat cat cannot jump up to unless she trims down. Keeping everyone on the food they are supposed to have is difficult but manageable. We just can't stand all this vomiting!! All three of them are healthy, no other symptoms. I am honestly beginning to wonder if vomiting is a learned/group behavior for cats. Is it possible that the other two learned it from the first cat and now they are just in this routine of vomiting that they cannot break? I've even tried separating their bowls so they do not feel competition when eating so they can eat slowly.
I've tried everything and I am at a loss. Any ideas?

[Jennicat]

If had I had a cat that was vomiting like that, I would definitely get them to the vet. The only reason we have Loki is that my boyfriend took him to the vet when he was vomiting... turns out he was having kidney problems, and probably would have gone into kidney failure had we not started medicating him and switched him to a prescription diet.

[Roofrabbit]

Vomiting is not a learned behavior, putting them on a hairball formula was a good call. We had the vomit routine going on with thirty cats at one feeding and it was very frustrating (and messy).
Try a strict feeding routine, twice a day without leaving any food out for them to "graze", always have fresh water out for them and see to it that they get enough exercise.
You may want to consider feeding the larger cat in a room by herself to make her feel special while the other cats eat their higher calorie meals. Remove all the food after about thirty minutes, so they know meal-time is over.

It's not much advice (sorry) but creating a more controlled environment may help narrow down the problem. It's helped us but every household is different and we still have a few cats that vomit after eating from time to time.
Good luck!