Our expectations can be remarkably powerful. The magic feather that Dumbo, the flying elephant, was told would help him fly, is a classic example of what is known as a placebo. The word placebo is Latin for “pleasing” and refers to an object that has no actual effect, other than to bolster our expectations.
In the early 70’s when I was a brand new psychology student, my study group was assigned to devise an experiment involving preschool children. I believe it was Thurmond Culpepper, a member of our group, who proposed that we study expectations and preschoolers’ memory for pictures. This evolved into the “Magic Cookie Study”.
In step one of our study, all the children were to be given a rather odd looking cookie to eat. This sugar cookie, covered with marshmallow and sprinkled with pink coconut, was to serve as the placebo.
Half of the class was to be told that the cookie was magic and would help them remember things perfectly. The other half of the kids were told that it was just a snack. Then we planned to test them by showing pictures of animals , and then recording how many of the animals they could recall five minutes later.
It turned out that most of the kids hated the cookies and not only refused to eat them but physically threw them at Thurmond while making fun of his name. Evidently coconut is not very popular with the preschool set, as many complained vocally about the pink hair on their cookies.
Also, it was nearly impossible to get them to sit down long enough to look at the animal pictures. And when it came time to telling us what animals they remembered, few subjects felt that this boring task was worth their time or effort, especially compared to throwing cookies or grabbing the experimenter’s stopwatch and dashing madly about the classroom. We did not demonstrate the placebo effect, but we did discover that our study group needed someone who actually knew something about kids.
Newsweek magazine science editor Sharon Begley has reported on a new placebo study published in the Archives of Internal Medicine. Daniel Cherkin at theGroup Health Center in Seattle compared the effectiveness of acupuncture, simulated acupuncture, and standard treatment on back pain. The researchers found that pain decreased significantly for 60% for both acupuncture groups, but only 39 % for the standard care patients. Although the results were used to support alternative approaches, like acupuncture, the most intriguing finding, as Begley points out, is that fake acupuncture (randomly getting poked with toothpicks) worked as well as real acupuncture, and twice as well as standard procedures.
A survey of Chicago area internists revealed that half of them used placebos with their patients. Twelve per cent, however, had ethical qualms and said that placebos should never be used. Most physicians, who used placebos, were somewhat cagey in what they actually told their patients– not wanting to lie outright, but also not wanting to diminish the benefits of positive expectations.
According to Fabrizio Benedetti of the Universityof Turin, a pioneer in placebo pain research, positive expectations can lead to the release of natural pain killers in the brain. The greater the expectations, the greater the relief that people feel. About 30% of the population appears capable of a strong placebo effect and magic cookies not withstanding, children have a greater response than adults.
According to MIT behavioral economist Dan Ariely, we associate the cost of medicines with their efficacy and this may be why expensive placebos work best and people claim that generic medications do not work as well as brand names. Placebo effectiveness is also related to factors such as exoticness, intrusiveness, and technological sophistication. Injections, for example are more potent that capsules, which in turn are better than tablets. Procedures associated with elaborate scientific looking equipment or arcane devices, also tend to have greater credibility.
One mental hospital used an impressive looking electroconvulsive shock machine to successfully treat depressed patients for many years. However a technician found that the machine had never been plugged in properly and it’s success was purely placebo effect.
The size of a pill is also related to its placebo value. As you might expect, if a little is good, a lot is great. When they feel bad, most people want the maximum strength possible. As comedian Jerry Seinfeld said, “We want them to figure what dose can kill us and then back off just a little.”
Placebo saline injections even helped some Parkinson patients in a study at theUniversityof British Columbia. The very brain chemicals that placebos stimulate, may actually help reduce some Parkinson Disease symptoms, such as stiffness and rigidity.
Placebos may also be effective when people learn, through association, that a particular experience is routinely followed by a specific response. This is known as classical conditioning. In a 1999 study, patients received several injections of a substance that quickly depressed their respiration. Later the injection of an inactive substance produced the same results. The nervous system had learned to associate all injections with the depressive response.
Similarly when kidney transplant patients were repeatedly given a strong anti-rejection medication, along with a distinctly flavored drink, the drink alone began to have the same beneficial effects as the medication. Begley says that this “was like finding that Kool-Aid can prevent organ transplant rejection”.
Harvard psychologist Robert Rosenthal and school principal Lenore Jacobson wrote a controversial book in 1968 entitled Pygmalion in the Classroom about their study in which teachers were told that certain (randomly selected) children had been scientifically identified as “late bloomers” and would show tremendous academic progress in the next school year . The teachers’ expectations were a self-fulfilling prophecy and the designated children showed a tremendous gains in achievement.
This research demonstrates that, not only our own expectations, but those of others, can result in a significant placebo effect. The story of the unplugged shock machine also dramatically displays this effect. In addition to the machine, the expectations of the attending staff influenced patients to the point that they exhibited sham seizures, when they thought shock was bring administered.
The placebo effect is a real testament to the power of our expectations. It also explains why I still want a big antibiotic pill every time I catch a cold, even though I know it doesn’t work on viruses. Maybe I should just eat a cookie instead.
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