Dmitry,
I would love to do a study about this - I spend alot of time at my tank, inside, in front, etc. I also see the tank more than 3 times a day - since you work odd hours, I am wondering how often you "interact" with your tank and how that affects the inhabitants.
When I first started, I had a 30g and barely saw it cause I worked so many hours and when I did interact with it, I was fiddling, rebuilding, moving rocks etc. My fish would do the same thing - freak out and hide. Interesting enough, they don't do that now and 4 of the 12 fish that I have now are from that same first tank . Emprical, no, it is what I observed.
Jim