A new theory was put forward proposing that the reason why some workers slowed down their effort towards the end of their day must result from some factor which was preventing these workers from keeping up their effort. The most likely factor was fatigue; workers were not strong enough or not sufficiently well nourished to keep their effort up all day. .
This led to research studies by Elton Mayo and his team from Harvard University. Their initial work in the 1920's found that workers (in a Philadelphia textile mill) who were given extra breaks and subsidized meals at work did improve their productivity; and when these extra rewards were taken away their effort fell back (see Mayo 1949). The research team then set up a major series of studies at the Hawthorne Works of the Western Electric Company which continued for ten years. Their aim was to study the effects of a range of fatigue-inducing factors such as levels of lighting, temperature, frequency of breaks, etc. in combination with an incentive payment by results system. .
If this research had produced the results expected at the outset, we would have had a prescription for high productivity based on lighting levels, temperature, frequency of meal breaks, health levels, etc. In some of their experiments the working environment was changed drastically to assess how this influenced productivity, but the results were a surprise at the time. There was a steady improvement in productivity throughout all the changes, even for instance when the lighting intensity was raised in imperceptible stages over a long period to a very bright intensity and then gradually reduced to that of a moonlit night. In their attempts to ensure that no other variables intervened in their experiments, the researchers had unwittingly changed one of the most important variables of all. They had increased the level of interest shown by the company in its employees, by regularly asking questions about their health, moral, personal lives, etc.
