What did Elton Mayo’s Hawthorne studies reveal about worker motivation?

"The classical era of management was followed by the human relations era, which began in the 1930s and focused primarily on how human behavior and relations affect organizational performance. The new era was ushered in by the Hawthorne studies, which changed the way many managers thought about motivation, job productivity, and employee satisfaction. The studies began when engineers at the Hawthorne Western Electric plant decided to examine the effects of varying levels of light on worker productivity—an experiment that might have interested Frederick Taylor. The engineers expected brighter light to lead to increased productivity, but the results showed that varying the level of light in either direction (brighter or dimmer) led to increased output from the experimental group. In 1927, the Hawthorne engineers asked Harvard professor Elton Mayo and a team of researchers to join them in their investigation. From 1927 to 1932, Mayo and his colleagues conducted experiments on job redesign, length of workday and workweek, length of break times, and incentive plans. The results of the studies indicated that increases in performance were tied to a complex set of employee attitudes. Mayo claimed that both experimental and control groups from the plant had developed a sense of group pride because they had been selected to participate in the studies. The pride that came from this special attention motivated the workers to increase their productivity. Supervisors who allowed the employees to have some control over their situation appeared to further increase the workers’ motivation. These findings gave rise to what is now known as the Hawthorne effect , which suggests that employees will perform better when they feel singled out for special attention or feel that management is concerned about employee welfare. The studies also provided evidence that informal work groups (the social relationships of employees) and the resulting group pressure have positive effects on"