Normalization of deviance, according to American sociologist Diane Vaughan, is the process in which deviance from correct or proper behavior or rule becomes culturally normalized.[1]
Vaughan defines the process where a clearly unsafe practice becomes considered normal if it does not immediately cause a catastrophe: "a long incubation period [before a final disaster] with early warning signs that were either misinterpreted, ignored or missed completely".[2] [3]
The original example cited by Vaughan is the events leading to the Space Shuttle Challenger disaster in 1986, but the concept has also been applied to aviation safety,[4] [5] clinical practice in medicine,[6] and the public's deviance from health measures aimed to stop the COVID-19 pandemic.[7]
Normalization of deviance can exist in conjunction with corporate omerta where deviation from rules is held up by a code of silence surrounding the deviations or an unspoken agreement on rhetoric within a group of executives. One of the reasons Lion Air Flight 610 and Ethiopian Airlines Flight 302 crashed was normalization of deviance based on a criticism of corporate omerta with a "culture of silence".[8]