Maintaining meaningful activity regulates psychological homeostasis , while general activities don’t. In other words; extreme emotions, thoughts, sensations and feelings are not necessarily a good thing, so participating in some activity that makes sense will make you feel more emotionally balanced: simply keeping doing something is not enough .
In other words, we need to maintain an affective balance. “Affection” is a technical way of talking about emotions, thoughts, sensations and feelings and how we act and make decisions.
On the other hand, there is both positive and negative affectivity, and everything depends on the balance between the two. We call this balance homeostasis, and this is where doing something that “makes sense” comes in, because the more sense what you do makes, the more balanced your affectivity will be.
This does not mean that such activity has to be our job, our profession or our business. It could be an extra activity we do a few hours a week, within a plan that allows the expression of our own affection, while giving us a sense of contribution and purpose towards others.
-  The Charles Sturt University and Melbourne Royal University Institute of Technology study: The more meaningful activity dampens the affectivity, the mere bustle increases it.
-  Article in the Web Research Digest of the British Psychological Society (UK College of Psychology) explaining the study.