The Incredibly Odd ‘Lady Macbeth Effect’

“Will all great Neptune’s ocean wash this blood / Clean from my hand?” —Lord Macbeth, Shakespeare’s ‘Macbeth’

In A Nutshell

Have you ever done something, shall we say, unethical? Did you feel the need to wash your hands? Researchers call this compulsion the “Lady Macbeth Effect,” and believe it or not, it actually exists outside of Shakespeare. Thanks to a strange slate of tests, researchers have determined the Lady Macbeth Effect is quite real . . . and might even make us horrible people.

The Whole Bushel

One of William Shakespeare’s most famous plays, Macbeth, tells the story of a power-hungry general who rises to power by (spoilers) murdering the king of Scotland. Of course, he never would have done the deed if it wasn’t for his wife, Lady Macbeth, egging him on. However, this femme fatale discovers it isn’t so easy killing a guy in cold blood, and soon she’s suffering a major attack of conscience.

Plagued by guilt, Lady Macbeth believes her hands are soaked in blood, and she’s soon scrubbing furiously at her fingers, trying to wash away the imaginary gore. Of course, Macbeth’s bride isn’t the only person—real or fictional—who’s tried to scour away their sins. In the Gospels, Pontius Pilate famously washed his hands after handing Jesus over to the mob for execution. In fact, so many guilty guys and gals have tried to moisten their mitts that researchers have come up with a catchy name for this odd phenomenon. They call it “The Lady Macbeth Effect,” and it’s pretty darn powerful.

In 2006, behavior researcher Chen-Bo Zhong (University of Toronto) and grad student Katie Liljenquist (Northwestern University) conducted a series of tests on a group of sinful subjects. First, researchers asked participants to think back to their past. A few were told to remember good deeds they’d done while others were asked to imagine their more unethical acts. Afterward, subjects were given sheets of paper and asked to finish incomplete words like “W _ _ H” and “SH _ _ ER.” As it turns out, people who recalled their shortcomings wrote “WASH” and “SHOWER” while people who remembered their altruism wrote words like “WISH” and “SHAKER.”

But Zhong and Liljenquist were just getting started. In a second test, subjects were asked to remember ethical or unethical actions and were then offered either pencils or antiseptic wipes. You probably won’t be shocked to learn that three-quarters of the people who mulled over their misdeeds chose wipes as opposed to just one-third of the do-gooders who made the same decision.

In a third test, participants were asked to write about something bad they’d done, and afterward, half were told to wash their hands. That’s when another scientist showed up and asked for volunteers for a new study he was working on. Of course, there was a catch. He couldn’t actually pay his volunteers so they’d be working for free. What happened next? Well, according to Zhong and Liljenquist, people who didn’t wash their hands were 50 percent more likely to help out. The folks who scrubbed their hands, however, weren’t so keen to volunteer.

So what does this all mean? Well, according to Zhong, “the cleanliness of one’s environment could have an impact on moral behavior.” Unfortunately, this impact isn’t always positive. Zhong fears that people who symbolically wash their hands might feel better about themselves despite their deeds and refuse to take responsibility for their actions. In other words, the act of rinsing gives them a feeling of forgiveness. Perhaps that’s why so many people say cleanliness is next to godliness.

Show Me The Proof

io9.com: The “Lady Macbeth Effect” Explains Why Bad People Wash Too Much
NY Times: The Lady Macbeth Effect