Lady Macbeth effect

The supposed Lady Macbeth effect or Macbeth effect is a priming effect said to occur when response to a cleaning cue is increased after having been induced by a feeling of shame.^[1] The effect is named after the Lady Macbeth character in the Shakespeare play Macbeth; she imagined bloodstains on her hands after committing murder.

In one experiment, different groups of participants were asked to recall a good or bad past deed, after which they were asked to fill in the letters of three incomplete words: "W_ _H", "SH_ _ER" and "S_ _P". Those who had been asked to recall a bad deed were about 60% more likely to respond with cleansing-related words like "wash", "shower" and "soap" instead of alternatives such as "wish", "shaker" or "stop".^[1]

In another experiment, experimenters were able to reduce choice-supportive bias by having subjects engage in forms of self-cleaning.^[2]

The effect is apparently localized enough that those who had been asked to lie verbally preferred an oral cleaning product and those asked to lie in writing preferred a hand cleaning product over the other kind of cleanser and other control items.^[3]

Other researchers have been unable to replicate the basic effect using larger samples.^[4][5] Replication difficulties have emerged for three out of four of Zhong and Liljenquist's original studies (i.e., Study 2, Study 3, and Study 4).^{[6][better source needed]} A meta-analysis of 15 studies examining the relationship between primes related to moral threat and cleansing preferences found a small effect, with no significant relationship evident across 11 studies conducted by researchers other than the original ones.^[7]

• Ritual purification
• Self-licensing
• Replication crisis