Research regarding morbidity of old people and responsabilities

Last year I heared on the radio that there was a research that had been conducted by some university (possibly the University of Montreal but I couldn’t tell for sure). The study discovered that in retirement homes, the old people that had responsabilities such as cooking, doing the dishes and taking care of a plant or small animal were in better shape, had less health problems and lived longer happier lifes than those for which everything was provided.

I found that very interesting at the time, but now I’m writing a paper for a Uni course, and I’m trying to find out who published that study. However I’m having quite some difficulty locating the article…

Anyone that know’s what I’m talking about? I just need a reference to give some credibility to what I’m saying in my paper (I’m not asking anyone to do my homework, nor trying to rip off someone elses work)

thanks