Not exactly morale, but this reminds me of this study in workplace procutivity
A researcher named Homer Hibarger had been testing theories about the effect of workplace illumination on worker productivity. His work, not surprisingly, had been sponsored by a maker of electric lightbulbs. While a group of female workers assembled telephone relays and receiver coils, Homer turned the lights up. Productivity went up. Then he turned the lights down. Productivity still went up! Puzzled, Homer tried a new series of interventions. First, he told the “girls” that they would be entitled to two five-minute breaks every day. Productivity went up. Next it was six breaks a day. Productivity went up again. Then he let them leave an hour early every day. Up again. Free lunches and refreshments. Up! Then Homer cut the breaks, reinstated the old workday, and scrapped the free food. But productivity barely dipped at all.
You should read the whole thing, written by a philosopher turned consultant, describing his experiences with management theories.
