Pseudoscience is simply false science. That is, anything that superﬁcially resembles science, yet isn’t science, is pseudoscience. The difference between them is one of degree rather than of kind, with no single clear boundary demarcating the essential difference. Although the boundaries are fuzzy, however, the distinction is a very important one, especially in the ﬁeld of psychology. As a relatively young science, which unlike physics or chemistry has yet to enumerate a set of ﬁxed principles that operate nearly universally, psychology is a discipline in which the distinction between real and false science is often unclear, especially to people outside the ﬁeld.
One major distinction between science and pseudoscience lies in the concept of falsiﬁability. A central feature (possibly the deﬁning characteristic) of science is the susceptibility of our hypotheses to refutation. In other words, for an idea to be considered scientiﬁc, it must be possible to conceive of evidence that could prove it wrong. An idea that cannot possibly be shown to be false is not scientiﬁc. It may be metaphysical, religious, or philosophical, but science is concerned with empirical testing of hypotheses, and testing an idea that cannot possibly be proven false is simply a waste of everyone’s time.
For example, the idea that colds are caused by microscopic organisms is easily falsiﬁable (or has been, at least, since the invention of good reliable microscopes). All that is necessary to prove this is to examine mucus from both sick and healthy individuals. If there is no difference in the number and kind of microorganisms found in the secretions of the two groups, the hypothesis was wrong. This begs several questions. What about the idea that disease is caused by mischievous invisible demons that have no physical substance? What evidence could prove it wrong? Well, scientists could argue that the demons don’t exist, because they don’t see them, but the retort is fairly obvious: “Of course you don’t see them, they’re invisible.” Ultimately, believing in them will come down to faith, not scientiﬁc physical evidence. The demon hypothesis is unfalsiﬁable because there is no way to demonstrate their existence, but also no way to prove their nonexistence, and it is therefore unscientiﬁc. This hypothesis is remarkably similar to the real-life argument made by sellers of subliminal perception self-help tapes. “Of course you can’t hear (or detect, with sensitive laboratory equipment) the hidden messages. They’re too quiet for you to hear.” The obvious question, then, is how can we establish that they are even there? If the answer is, “You can’t,” then we are dealing with pseudoscience rather than science.
Beyond the lack of falsiﬁability, there is a set of characteristics typically found in pseudoscience that may help you to identify it (with a thank you to Bunge, 1984).
- Reversed Burden of Proof—In science, the burden of proof is on the claimant.
If a person proclaims that something is true, then they must produce evidence to support that claim. Without evidence, there is no expectation that anyone will believe the claim. In pseudoscience, this burden is shifted to the critic. Rather than providing compelling evidence that he can actually communicate with the dead, a medium may demand proof that he can’t. This puts the scientiﬁc critic in a difﬁcult position, because the scientiﬁc method cannot prove a negative.
This counterintuitive idea is well illustrated by an example that James Randi has frequently used to demonstrate the absurdity of a reversed burden of proof. First, assume that millions of people have come to believe that once a year, in the dead of winter, a large man in a red suit pilots a ﬂying sleigh around the world, pulled by eight caribou or reindeer. The skeptical reader, may say, “But that’s absurd! Reindeer can’t ﬂy!” The response from the true believer? “Prove it!” So, the skeptic sets out to prove that reindeer can’t ﬂy. This will require taking some reindeer into the air, either aboard an aircraft of some sort or to the top of a tall building, maybe Rockefeller Center in New York City. On the roof, the ﬁrst animal is led up to the edge and given a good push. Sadly, it fails to ﬂy. How many more reindeer carcasses would have to pile up on the ice rink below before the point was considered proven? Unfortunately, all that has been demonstrated is that those reindeer couldn’t ﬂy, or chose not to ﬂy for reasons unknown, or were depressed and suicidal and welcomed the chance to end it all. For the Santa-supporters to prove their side of the argument, all they would have to do is produce, for public examination, one actual ﬂying reindeer.
- Overreliance on Testimonials and Anecdotal Evidence—Real science uses controlled experimental designs, with results that are reproducible by other experimenters, not biased reports of individual people’s uncontrolled personal experiences.
Right now, for example, there are clinics in California and Mexico that claim to prevent or cure cancer via the regular administration of coffee enemas. No controlled clinical trials have ever even hinted at the possibility that such a treatment might be effective, nor is there any good reason to believe that it would be, but the clinics are happy to provide evidence when asked. Unfortunately, the evidence consists of personal statements from people who believe the treatment worked for them. Missing is any medical evidence that these people ever had a proper medical diagnosis of cancer or have actually been cured of anything. The use of testimonials in television advertising is often taken to an absurd degree. One memorable ad for headache medicine, for example, featured treatment recommendations from a soap opera actor who presented his credentials thusly: “I’m not a doctor, but I play one on TV.” To confuse this approach with scientiﬁc evidence is inappropriate.
- Emphasis on Conﬁrmation Rather Than Refutation—Experimental design and statistical analysis in psychology are built around asking the question, “If I am wrong, could I have gotten these data anyway?” If other plausible alternative explanations for our results can be ruled out, only then can a hypothesis be accepted.
The true mark of a pseudoscientist, on the other hand, is the willful ignoring of evidence that fails to support a hypothesis, while clinging to any bit of evidence that seems to support it. Psychic investigators have sometimes ignored famous psychics’ complete failure to produce their claimed effects (blaming the failure on other factors), while emphasizing the testimonials of witnesses to the effects under less controlled conditions.
- Overuse of Ad Hoc Hypotheses to Escape Refutation—An ad hoc hypothesis is simply one that gets invented on the spot, rather than one that was already part of the theory.
Speaking of psychics, the list of excuses provided to explain away their failures (the hypothesis that their powers don’t exist is rarely considered) is nearly endless—here are a few of the more popular ones: “The skeptical people present are sending out negative vibrations that interfere with the powers, gifts, spirits, etc.” For some reason, being watched very closely by people who might spot cheating tends to shut the psychic powers down; “Of course he cheated this time, the powers weren’t working properly, and he didn’t want to disappoint you. But he usually doesn’t cheat, and his powers are real”; “He got more wrong than we would expect by chance, that means negative psi is at work here, which is just as impressive as the positive kind.”
- Absence of Self-Correction—No amount of evidence ever seems to get rid of a theory. True science is self-correcting over time. Theories that turn out not to be true tend to be dropped in favor of theories that are better supported by evidence.
In medicine, for example, the accumulation of evidence on the actions of microorganisms eventually led to the disappearance of the humoral theory of disease (that disease is caused by an excess of blood or bile, for example) in favor of the germ theory of disease. Within psychology, for example, some psychoanalysts have continued to view autism as a response to poor parenting in early childhood, despite the solid evidence that the disorder has physiological underpinnings and a genetic component.
- Use of Obscurantist Language—This simply refers to the pseudoscientist’s tendency to use hazy, scientiﬁc-sounding language, that doesn’t necessarily make any sense, to sound rigorous and complicated.
- Ron Hubbard’s DIANETICS (1950) is ﬁlled with classic examples. Here’s a favorite:
The scientiﬁc fact, observed and tested, is that the organism, in the presence of physical pain, lets the analyzer get knocked out of circuit so that there is a limited quantity or no quantity at all of personal awareness as a unit organism.
One can read and reread the section of the book in which it appears and still have no idea what it means.
- Absence of Connectivity with Other Disciplines—In pseudoscience, it is not unusual for a claim to require that a large area of human knowledge be wrong in order for the claim to be true.
Uri Geller, an Israeli psychic famous in the 1970s, claimed that he could bend metal objects using only the power of his mind. This can only be true if modern physics, chemistry, psychophysiology, and metallurgy are simply ﬂat-out wrong about how the world works, and yet books celebrating his “gifts” remain in print and continue to be written.
As psychologists, we should be very concerned about the inﬂux of pseudoscience into our ﬁeld, especially in the clinical realm. A gulf has developed between psychological scientists and clinicians, with a number of therapies being widely promoted despite a lack of empirical support, and sometimes despite not especially making any sense.
- Bunge, M. “What Is Pseudoscience?” Skeptical Inquirer, 9 (1984): 36–46;
- Lilienfeld, S. O. “Pseudoscience in Contemporary Clinical Psychology: What It Is and What We Can Do about It.” The Clinical Psychologist, 51(4) (1998): 3–9.