What factor was varied in the Hawthorne experiments to measure its effect on worker productivity?

The Hawthorne experiments, conducted in the 1920s and 1930s at the Western Electric Hawthorne Works in Illinois, primarily aimed to investigate how different environmental changes affected worker productivity. The key factor that was systematically varied during these experiments was the lighting levels. Researchers observed that as they changed the intensity of lighting – both by increasing and decreasing it – there was a noticeable impact on how productive the workers were.

Interestingly, they found that productivity increased regardless of whether lighting was improved or diminished, which led to the conclusion that social factors and the attention given to workers were significant influences on productivity rather than the physical working conditions alone. This phenomenon became known as the Hawthorne effect, highlighting the psychological aspect of worker performance influenced by their awareness of being observed and studied. This understanding laid foundational insights into human behavior in organizational settings and contributed to theories of management and motivation.