Lady Macbeth, a character from Shakespear’s play “Macbeth”, after conspiring to assassinate King Duncan, would repetitively wash her hallucinatory blood-stained hands in order to atone for her sins.
The Lady Macbeth Effect is a psychological state whereby people who feel guilty about a wrong doing have a desire to wash their hands or body to clear their conscience. They tend to believe that moral purity can be replaced by physical purity.
Almost every culture and religion relates moral and bodily purification. Two researchers — Chen-Bo Zhong and Katie Liljenquist have published a paper in the journal Science contending that the link is more than metaphorical. They outlined evidence of a “Macbeth Effect” in social psychology: “a threat to people’s moral purity induces in them a need to seek to cleanse themselves.”
The psychologists Jedediah Siev, Shelby Zuckerman, and Joseph Siev conducted a meta-analysis of the available papers on the Macbeth effect so far. Although the effect sizes observed in the pioneering three studies were moderate, there was no effect in all the 11 independent replication attempts.
In other words, it seems that the magnitude of the Macbeth Effect has been excessively hyped. It’s so frequent that big, snazzy findings like this and a handful of others are swiftly published in university press releases and believed to be true by many followers of popular sciences. Yet efforts to replicate early, exciting effects have usually either failed or have revealed something notably less exciting.
– Urveez Kakalia and Dhara Mehta.