Hawthorne Effect

The Hawthorne Effect describes the phenomenon where people modify their behavior when they know they are being observed — named after studies conducted at Western Electric's Hawthorne plant in the 1920s and 1930s, where productivity appeared to improve in response to virtually any change in working conditions, later attributed to the act of observation itself rather than the specific change. In HR practice, the Hawthorne Effect is most relevant in performance management and engagement research: employee behavior and productivity can change simply because a performance improvement program is running, making it difficult to attribute observed improvements to the program's content rather than the attention it represents. This does not invalidate the interventions — the attention itself may be genuinely valuable — but it complicates ROI measurement for HR programs.