Donate to the Igs

Is “MacBeth Effect” research cursed?

By happy, horrified tradition, theater folk hesitate to name a certain Shakespeare play, for fear bad things will then happen. A noted psychology study that (albeit not being a theatrical endeavor) did explicitly name that play now seems to have had something bad happen. A new study brings (and is!) the bad news:

Out, Damned Spot: Can the ‘Macbeth Effect’ Be Replicated?Brian D. Earp [pictured here], Jim A. C. Everett, Elizabeth N. Madva and J. Kiley Hamlin, Basic and Applied Social Psychology, vol. 36, no. 1, 2014, pp. 91-98. (Thanks to investigator Neil Martin for bringing this to our attention.) The authors, at Yale University, University of Oxford, Weill Cornell Medical College, University of British Columbia, explain:

brianearp“Zhong and Liljenquist (2006) reported evidence of a “Macbeth Effect” in social psychology: a threat to people’s moral purity leads them to seek, literally, to cleanse themselves. In an attempt to build upon these findings, we conducted a series of direct replications of Study 2 from Z&L’s seminal report. We used Z&L’s original materials and methods, investigated samples that were more representative of the general population, investigated samples from different countries and cultures, and substantially increased the power of our statistical tests. Despite multiple good-faith efforts, however, we were unable to detect a “Macbeth Effect” in any of our experiments.”

The old, possibly cursed study to which the new (also possibly cursed) study refers is:

Washing away your sins: Threatened morality and physical cleansing,” Chen-Bo Zhong and Katie Liljenquist, Science, vol. 313, no. 5792, 2006, pp. 1451-1452.

Here is the passage of the play that gave the effect its name:

Improbable Research