Demons Where Once There Were None

Exploring the darker powers of suggestion

Salman Rushdie wrote in Midnight’s Children that memory “selects, eliminates, alters, exaggerates, minimizes, glorifies, and vilifies also; but in the end it creates its own reality, its heterogeneous but usually coherent version of events; and no sane human being ever trusts someone else’s version more than his own.” To this I would add that what one believes to be her own version may be someone else’s. What can people be persuaded, knowingly or not, to believe? Researchers once convinced four college students that as children they had probably witnessed demonic possession.

In 2001, psychologists Giuliana Mazzoni, Elizabeth Loftus, and Irving Kirsch invited a large group of students at the University of Florence in Italy to fill out questionnaires. The students categorized different events in two ways: how plausible the event was, and how certain the student was that she had (or had not) experienced it as a young child. Some of the events were mundane, but this doozy was also included—“witnessed possession.” Some of the students who had believed demonic possession to be highly implausible and were quite certain they had not ever witnessed a possession were invited back.

At the next session, which took place three months later, researchers began chipping away at the first of the students’ convictions: that witnessing demonic possession was an implausible occurrence. Under the pretense of gauging their “readability,” the students read a dozen short stories, three of which were about demonic possession. One story presented the notion that possession occurs quite frequently in Italian culture, another contained the testimonies of people who’d witnessed possession-like behavior, and the third included mention of “typical” symptoms of possession (i.e., “convulsing, falling down, foaming at the mouth, swearing, vomiting hair, and spontaneous movement of objects”).

In the third session, a week later, things got personal. The students completed another questionnaire, this time about their fears. But regardless of how the students responded, they were individually informed that their “fear profile” was consistent with having witnessed possession before the age of three.

Finally, after another week, students returned to the lab to fill out the same set of plausibility and certainty questionnaires they’d completed in the original session.

So what happened to their ratings? On average, the 22 students who’d persevered through all four sessions judged “witnessing possession” to be both significantly more plausible and something they were likelier to have experienced as young children. (Control participants who merely completed the questionnaires twice, or who received stories and “fear profile” feedback about an unrelated event, did not show this pattern.) Importantly, most students still thought they probably had not witnessed possession; they were merely less certain about this than they’d been a few months earlier. But four of the students did an about-face and claimed that, more likely than not, they had. That’s right: three page-long stories and a bogus “fear profile” were enough to convince nearly 20 percent of the students that they’d probably witnessed demonic possession.

Memory needn’t be suggested—psychologists often use the more insidious term “implanted”—to be false. I recall a meal with a colleague at a fancy Montreal restaurant in vivid detail, down to the robin-egg blue of my cocktail, but my colleague maintains that she “didn’t even go to the conference in Montreal.” The memory is something of a fluke—it is other cities, other meals, and other cocktails, all jumbled together until they no longer resemble themselves—and the fluke is generated in-house.

Finally, two caveats. The sample size of the study I just described was small (though the literature is littered with other, similar—if less sensational—studies). And the set-up—all those questionnaires!—was hardly realistic. Perhaps, after hearing so much talk of demonic possession, students were just telling an earnest, likeable experimenter what they thought he wanted to hear.

And yet, isn’t that how suggestion so often begins, with an overly helpful psychotherapist, or a hard-working cop who wishes very badly you’d seen something you have not?

If, indeed, you have not.

Permission required for reprinting, reproducing, or other uses.

Jessica Love holds a doctorate in cognitive psychology and edits Kellogg Insight at Northwestern University’s Kellogg School of Management.

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