Related Experiment Video
Updated: May 28, 2026
08:32
Large Volume, Behaviorally-relevant Illumination for Optogenetics in Non-human Primates
Published on: October 3, 2017
Shining new light on the Hawthorne illumination experiments
Masumi R Izawa1, Michael D French, Alan Hedge
1Cornell University, Ithaca, New York 14853-4401, USA.
Human Factors
|November 4, 2011
Summary
This study re-analyzed Hawthorne illumination experiment data, finding inconsistent evidence of lighting affecting worker productivity. The experiments were seriously flawed, challenging the popular "Hawthorne effect" narrative.
Area of Science:
- Industrial-organizational psychology
- Organizational behavior
- Human factors research
Background:
- Revisiting the seminal Hawthorne illumination experiments using newly discovered archival data.
- Addressing inconsistencies in previous accounts based on secondary sources.
- Challenging the long-held consensus that light levels did not affect worker productivity.
Observation:
- Archival materials, including reports, notes, and productivity data, were meticulously examined.
- Statistical analysis was performed on data from all three illumination experiments.
- Previously unpublished details of the experimental procedures were uncovered.
Findings:
- Inconsistent evidence emerged regarding the association between light levels and worker productivity.
- A minor effect was observed in one treatment sequence but not replicated.
- All three illumination experiments were identified as having significant methodological flaws.
Implications:
- This research questions the validity of the popular interpretation of the "Hawthorne effect."
- The identified shortcomings highlight critical considerations for designing future field studies.
- Re-evaluation of historical industrial psychology experiments is crucial for accurate understanding.
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