Maybe my memory is bad, and I did not have time to read the links, but I thought at least some of the experiments into the "Hawthorne effect" involved groups of employees, as in if you either brighten or dim the lights from the normal you get a short-term increase in productivity. Anyway...
Catching people doing things right and praising their work, and talking to them and getting their opinions and in general having frequent and open communication, is just common decency and good business sense to me, although guys like Blanchard included it in their books, I believe, because so many so-called Managers and Leaders don't exercise common decency and good business sense! It is amazing to me sometimes.
Although I agree the problem is often the system (perhaps the majority of the time) and this is where to look first, sometimes it IS the individual employee that is the problem, IMO, and one individual can have a severe negative effect on the overall business. I've seen it too often, and don't buy the thinking that somehow it always goes back to the system.
My personal management philosophy as it relates to employees is to simply treat them as I would like to be treated in the same situation. I can usually think about a situation for a few minutes and know what I should do. Overly simplistic? Not really, IMO, -- this thought process covers over 95% of the situations I ever had to deal with. The exceptions I seek help on. So, I do believe in measuring to some degree the performance of individuals. A search will turn-up a long thread we had on this subject about 6 months ago on the subject of employee reviews and performance rating. Some experts say trashcan employee reviews altogether, a process I cannot yet agree with. I don't mind being measured -- I expect it -- as long as the measure is a fair one. An unfair measure can have a more negative effect than no measure at all, but a good and fair measure is the best situation IMO.