Science versus Austrian (and later British) philosopher of

science Sir Karl Popper; we begin with his

Pseudoscience conceptualization.
Scott O. Lilienfeld,1 Steven Jay Lynn,2 Popper
and Rachel J. Ammirati1
1 Emory University, U.S.A. and 2 Binghamton According to Popper (1959), scientific claims
University, U.S.A. are falsifiable: They are in principle capable
of being proven false (according to Popper,
scientific claims can never be proven true;
The prefix “pseudo” means “false.” Accordingly, they can only be falsified). In contrast, Popper
pseudoscience is false science. Yet equating maintained, pseudosciences are impossible
pseudoscience with false science is not entirely to falsify, either because their proponents (a)
accurate, because most false scientific claims
advance claims that are so vague that they are
are not pseudoscientific. Instead, we can best
untestable or (b) continually invoke ad hoc
view pseudosciences as fake sciences that
hypotheses—escape hatches or loopholes—that
display (often intentionally, but sometimes
effectively immunize their claims from refu-
unintentionally) the superficial appearance of
tation. Eventually, the overuse of ad hoc
science but largely lack its substance (Hines,
hypotheses can place claims outside of the
2002). Nevertheless, distinguishing “fake”
purview of scientific testing. For example,
science from both genuine science and other
Popper argued that much of Freudian theory
forms of false science is more easily said than
is pseudoscientific, because no conceivable
done (Pigliucci & Boudry, 2013). The question
evidence could disprove it. For example, Pop-
of how to differentiate pseudoscience from
per considered Freud’s concept of the Oedipus
other disciplines bears significant implications
complex (the idea that young children are
for clinical psychology and allied mental health
romantically attracted to the opposite-sex
fields, because numerous authors contend that
parent) as unfalsifiable and therefore pseu-
these fields’ scientific foundations are being
doscientific. If a psychoanalytic researcher
increasingly eroded by pseudoscientific prac-
were to find that most adults recall a time
tices (e.g., Lilienfeld, Lynn, & Lohr, 2003;
when they were romantically attracted to
McFall, 1991, 2001). Moreover, mental health
their opposite-sex parents, she could interpret
consumers, practitioners, and researchers
this finding as confirming Freud’s hypothesis
would benefit from guidance in separating
of the Oedipus complex. In contrast, if this
scientific from pseudoscientific claims, largely
researcher were to find that most adults do
because the latter assertions can fool even
not recall such a time, she could interpret this
well-trained individuals (Herbert, 2002).
finding as implying that adults find memories
of romantic attraction toward their parents
The Demarcation Problem to be so threatening that they repress them.
The “demarcation problem” refers to the This “heads I win, tails you lose” reasoning,
challenge of distinguishing science from non- according to Popper, renders Freudian theory
science, including pseudoscience (Pigliucci & difficult or impossible to falsify and therefore
Boudry, 2013). To this day, there is no uni- pseudoscientific.
versally agreed upon solution to this problem. Nevertheless, few scientists believe that Pop-
Perhaps the best-known attempt to resolve per’s falsifiability criterion, important as it is,
the demarcation problem was offered by the succeeds as a necessary or sufficient criterion

The Encyclopedia of Clinical Psychology, First Edition. Edited by Robin L. Cautin and Scott O. Lilienfeld.
© 2015 John Wiley & Sons, Inc. Published 2015 by John Wiley & Sons, Inc.
DOI: 10.1002/9781118625392.wbecp572
2 SCIENCE VERSUS PSEUDOSCIENCE

for distinguishing science from pseudoscience. retreat” to the protective belt, thereby invoking
For one thing, certain pseudoscientific claims ad hoc hypotheses that could explain away the
do appear to be capable of refutation. For negative findings. In doing so, these advocates
example, although astrology is a prototypical tinker with the theory’s auxiliary hypotheses
pseudoscience, many of its claims, such as in an effort to salvage their theory from fal-
the proposition that astrological signs are cor- sification. In certain cases, strategic retreats
related with personality traits, are falsifiable, are justifiable in science, especially when they
and have been essentially falsified (Carlson, enhance the theory’s content, predictive power,
1985). Moreover, several critics have argued or both. Yet, when strategic retreats to the
that contra Popper, many scientific claims protective belt are merely “pasted on” to the
are difficult or impossible to falsify. Specifi- theory in desperate attempts to rescue it from
cally, because legitimate scientists can almost falsification, such retreats become problematic.
always invoke ad hoc hypotheses to rescue According to Lakatos (1975), in progressive
their claims from refutation, these claims may research programs, theory tends to precede
never be strictly disproven, a view known data. The hard core of the theory generates
as the Duhem–Quine thesis after the two novel predictions that are generally corrobo-
philosophers who propounded it. rated by findings. In contrast, in degenerating
research programs, data tend to precede the-
Lakatos ory. Negative findings—those that challenge
An alternative perspective on the demarcation the theory’s hard core—repeatedly emerge,
problem derives from Hungarian philosopher and the theory’s advocates continually invoke
of science Imre Lakatos. According to Lakatos auxiliary hypotheses within the protective belt
(1975), scientific theories, or as he called them in an effort to keep the sinking theory afloat.
“research programs,” possess two major com- The theory is not moving forward; it is merely
ponents: (a) a “hard core” of fundamental trying to keep up with the accumulating influx
presuppositions that is integral to the theory of negative findings. Yet, as Lakatos noted,
and (b) a “protective belt” of auxiliary (sec- because some degenerating research programs
ondary) hypotheses that are not central to the do eventually right themselves by amending
theory but that help to protect the theory from their protective belts (cognitive dissonance
refutation. For example, the existence of the theory is arguably a potential example in
unconscious comprises part of the hard core of psychology; see Greenwald & Ronis, 1978),
psychoanalytic (Freudian) theory. It is difficult it is not necessarily illegitimate to cling to a
to imagine calling oneself psychoanalytic in degenerating research program, just so long
theoretical orientation without endorsing the as one honestly admits to oneself and others
core assumption of unconscious processing. that it is degenerating. What is illegitimate is to
In contrast, the existence of the defense mech- pretend that a degenerating research program
anism of reaction formation (the supposed is in good scientific shape.
tendency to deal with an anxiety-provoking Lakatos’ framework provides a useful way
emotion, such as hatred, by transforming it of conceptualizing the difference between
into its opposite, such as love) almost certainly science and pseudoscience. Specifically, from a
resides in the protective belt of psychoanalytic Lakatosian perspective, we can define pseudo-
theory. One could legitimately call oneself psy- sciences as degenerating research programs that
choanalytic, although perhaps not an orthodox its proponents claim are progressive. In the case
Freudian, even if one rejected Freud’s concept of pseudoscientific theories or methods, claims
of reaction formation. are not supported by evidence, yet adherents
According to Lakatos, when data repeatedly of these theories or methods insist that they
conflict with a theory’s hard core, proponents are. As a consequence, these adherents are
of this theory typically perform a “strategic deceiving themselves, deceiving others, or
 SCIENCE VERSUS PSEUDOSCIENCE 3

both. As helpful as Lakatos’ conceptualization dividing line between day and night (hence the
is, it does not offer a strict set of criteria for equally fuzzy concepts of dusk and dawn), we
demarcating progressive from degenerating can still distinguish morning from night for
research programs. For example, when a the- most pragmatic purposes (Leahey & Leahey,
ory’s predictions are met with mixed results, 1983). Similarly, we can differentiate clear-cut
how do we decide whether it is progressive or sciences from clear-cut pseudosciences, even
degenerating? Nevertheless, this may not be a though the distinction inevitably becomes
fundamental flaw within a Lakatosian frame- murky in certain cases.
work, because strict criteria for distinguishing According to the family resemblance per-
science and pseudoscience may not exist. spective, pseudosciences are characterized by a
set of useful, albeit fallible, indicators (Bunge,
Pseudoscience: A Family 1984). We can think of these indicators as
Resemblance View “warning signs” of pseudoscience. Although
no single criterion is dispositive of a theory’s
Indeed, some eminent philosophers of science
status as a pseudoscience, the more criteria are
(e.g., Laudan, 1983) have declared the demar-
present, the more skeptical of this discipline we
cation problem dead, because there appears to
should typically become. Here we present 10
be no single criterion—or set of criteria consid-
warning signs of pseudoscience that are useful
ered jointly—that can invariably be used to dis-
for distinguishing pseudoscientific from scien-
tinguish science from pseudoscience. Some of
tific claims in clinical psychology, psychiatry,
these scholars have gone further, recommend-
social work, and allied fields (Lilienfeld et al.,
ing that the very concept of pseudoscience be
2003).
abandoned.
Still, there is an alternative. According to Overuse of Ad Hoc Hypotheses Designed
a family resemblance view of pseudoscience to Immunize Claims from Falsification
(Pigliucci & Boudry, 2013), there is no “bright When taken to an extreme, ad hoc hypotheses
line” distinguishing science from pseudo- can provide virtually impermeable barriers
science. Yet just as first-degree relatives within against falsification. In other words, when one
a biological family typically share a loosely overuses ad hoc hypotheses, one is attempting
correlated set of facial features, allowing us to to explain away findings that are inconsistent
distinguish them from members of other fam- with a claim. For example, proponents of a
ilies, pseudosciences tend to exhibit a loosely new psychotherapy might insist that negative
correlated set of characteristics. According to findings are due to inadequate training of the
this view, pseudoscience is an “open concept” individuals delivering the treatment. Although
(Pap, 1953). Open concepts are characterized this ad hoc hypothesis might be true, it cannot
by (a) fuzzy boundaries, (b) an indefinitely stand on its own; it itself requires systematic
extendable indicator list, and (c) an unclear testing. Otherwise, it becomes what Dawes
inner nature. If pseudoscience is an open (1994) termed an “argument from a vacuum:”
concept, the distinction between science an assertion advanced in the absence of any
and pseudoscience is one of degree rather supportive evidence.
than kind.
The fact that one cannot draw a clear line Absence of Self-Correction
in the sand distinguishing science from pseu- Like the assertions within pseudoscientific
doscience does not imply that most scientific disciplines, the assertions within most sci-
claims cannot be distinguished from most entific disciplines are incorrect in certain
pseudoscientific claims in clinical psychology respects. Nevertheless, in the long run,
or related disciplines. As the psychophysicist S. most scientific research programs tend to
S. Stephens observed, although there is no clear learn from and correct errors, whereas most
4 SCIENCE VERSUS PSEUDOSCIENCE

pseudoscientific research programs do not. strategy is not an efficient means of rooting out
Consequently, intellectual stagnation is a error in one’s web of beliefs. In fairness, how-
hallmark of most pseudoscientific research ever, confirmation bias—the tendency to seek
programs. For example, astrology has changed out evidence consistent with one’s hypotheses,
remarkably little over the past 2,500 years and to deny, dismiss, or distort evidence that
despite enormous advances in planetary and is not—is not unique to pseudosciences and is
stellar science (Hines, 2002). a serious problem in some sciences, including
medicine, as well (Ioannidis, 2008).
Evasion of Peer Review
Many proponents of pseudoscience avoid Reversal of the Burden of Proof
subjecting their work to the crucial safeguard The burden of proof in science typically falls
of peer review, which is an essential means squarely on individuals who put forth a claim,
for identifying errors in authors’ reasoning, not on critics of this claim. Proponents of pseu-
methodology, and analyses. They may do so doscience often insist that skeptics demonstrate
on the grounds that the peer-review pro- beyond a reasonable doubt that a claim (e.g., an
cess is biased against findings that contradict assertion regarding the efficacy of a novel psy-
well-established paradigms or that their asser- chotherapy) is false. This error is similar to the
tions cannot be evaluated adequately using logician’s ad ignorantium fallacy (the argument
standard scientific methods. For example, from ignorance), the mistake of assuming that
advocates of graphology (handwriting analy- a claim is likely to be correct because there is no
sis intended to infer personality traits) have convincing evidence against it.
rarely subjected their claims to peer review. Absence of Connectivity
By avoiding or circumventing the peer-review In contrast to scientific research programs,
process, proponents of pseudoscience forfeit pseudoscientific research programs tend to lack
an invaluable opportunity to obtain corrective “connectivity” with other scientific disciplines
feedback from informed colleagues. (Stanovich, 2012). In other words, pseudo-
Emphasis on Confirmation rather than sciences often purport to create novel para-
Refutation digms out of whole cloth rather than to build
on extant, well-supported ideas. For example,
Nobel Prize-winning physicist Richard Feyn-
many proponents of extrasensory perception
man (1985) maintained that the essence of
(ESP) argue that it is a genuine—although
science is a bending over backwards to prove
heretofore undetected—physical process of
oneself wrong. Popper’s student Bartley (1962)
perception, even though reported cases of ESP
similarly argued that science entails the max-
violate almost every major law of physical
imization of constructive criticism. Ideally,
signals (e.g., ESP purportedly operates just as
scientists subject their cherished claims to
strongly from thousands of miles away as it
the risk of refutation (Meehl, 1978; see also
does from a few feet away). Although scientists
Ruscio, 2002). In contrast, pseudoscientists should remain open to the possibility that
tend to seek only confirming evidence for their an entirely novel paradigm has successfully
claims. For example, if the developers of a overturned all preexisting paradigms, they
treatment for a psychological disorder request must insist on high standards of evidence
feedback from clients to help them “prove” before drawing this conclusion (Wagenmak-
that the treatment is effective, they will avoid ers, Wetzels, Boorsbom, & van der Maas,
important information that could show that 2011).
the treatment is ineffective, or even harmful.
Because a determined advocate can find at Overreliance on Anecdotal Evidence
least some supportive evidence for virtually Anecdotal evidence or “anecdata” can be
any claim, a confirmatory hypothesis-testing quite useful in the early stages of scientific
 SCIENCE VERSUS PSEUDOSCIENCE 5

investigation. Nevertheless, such evidence is for the efficacy of eye movement desensiti-
almost always more helpful in the context zation (EMDR), a controversial treatment
of discovery (hypothesis generation) than for posttraumatic stress disorder and related
in the context of justification (hypothesis conditions:
testing; see Reichenbach, 1938). Proponents We propose that the repetitive redirecting of
of pseudoscientific claims frequently invoke attention in EMDR induces a neurobiological
reports from selected cases (e.g., “This treat- state similar to that in REM sleep, which is
ment clearly worked for Person X, because optimally configured to support the cortical
Person X improved following the treatment”) integration of traumatic memories into general
as a means of furnishing dispositive evidence semantic networks. We suggest that this integra-
tion can then lead to a reduction in the strength
for these claims. For example, proponents
of hippocampally mediated episodic memories
of unvalidated treatments (e.g., facilitated of the traumatic event as well as the memories’
communication, secretin, gluten-free diets, associated, amygdala-dependent negative affect.
chelation therapy) for autistic spectrum dis- (Stickgold, 2002, p. 61)
order have often pointed to uncontrolled
case reports of improvement as supportive Absence of Boundary Conditions
evidence. As Gilovich (1991) observed, case Most well-supported scientific theories pos-
reports almost never provide sufficient evi- sess boundary conditions: well-articulated
dence for a claim, although they often provide limits under which hypothesized phenomena
necessary evidence for a claim. For example, should and should not occur. In contrast, many
if a new form of psychotherapy is efficacious, pseudoscientific phenomena are purported to
one should certainly expect at least some operate across an exceedingly wide range of
positive case reports of improvement. Nev- conditions and individuals. As Hines (2002)
ertheless, such case reports do not provide noted, one common characteristic of fringe
adequate evidence that the improvement was psychotherapies is that they are ostensibly
attributable to the psychotherapy, because this efficacious for almost all disorders regardless
of their causes. For example, some proponents
improvement could have been generated by
of thought field therapy, a widely used “energy
a host of extraneous influences (e.g., placebo
therapy,” have proposed that this treatment is
effects, regression to the mean, spontaneous
beneficial for virtually all mental disorders. The
remission, maturation; Lilienfeld, Ritschel,
developer of this treatment has even posited
Lynn, Cautin, & Latzman, 2013).
that it is effective not only for adults, but for
Use of Obscurantist Language “horses, dogs, cats, infants, and very young
Many proponents of pseudoscience resort to children” (Callahan, 2001, p. 1255). Although
impressive-sounding or technical jargon in it is certainly possible that a therapy derived
an effort to provide their disciplines with the from a well-supported scientific theory could
effectively treat a wide variety of disorders (e.g.,
superficial trappings of science. Such language
cognitive behavioral therapy; Butler, Chapman,
may seem persuasive to individuals unfamil-
Forman, & Beck, 2006), therapies of this nature
iar with the scientific underpinnings of the
are rare.
claims in question, and may therefore lend
these claims an unwarranted imprimatur of The Mantra of Holism
scientific legitimacy. The ascendancy of neuro- Proponents of pseudoscientific claims, espe-
scientific explanations of behavior (Satel & cially in mental health, often resort to the
Lilienfeld, 2013) over the past two decades has “mantra of holism” (Ruscio, 2002) to explain
rendered questionable explanations that invoke away negative findings. When invoking this
neurological concepts especially popular. For mantra, they typically maintain that scientific
example, consider the following explanation claims can be evaluated only within the context
6 SCIENCE VERSUS PSEUDOSCIENCE

of broader claims and cannot be judged in must be something to it”). Nevertheless,

isolation. For example, some proponents of researchers have not examined whether these
the Rorschach inkblot test have responded to or other putative indicators of pseudoscience
criticisms of this technique by asserting that we have delineated are intercorrelated, as
clinicians virtually never interpret results from would be anticipated of a family resemblance
a Rorschach in isolation. Instead, in actual model.
practice clinicians consider numerous pieces The distinction between science and pseudo-
of information, only one of which may be science has been one of the most contemplated
a Rorschach protocol. There are two major and debated issues in philosophy of science,
difficulties with this line of reasoning. First, it and it bears potentially important implications
implies that clinicians can mentally integrate for distinguishing well-supported from poorly
a great deal of complex psychometric infor- supported claims in clinical psychology and
mation from diverse sources, a claim that is allied disciplines (Lilienfeld et al., 2003). The
dubious given the research literature on clinical question of how to differentiate science from
judgment. Second, by invoking the mantra of pseudoscience is not fully resolved, and the
holism, proponents can avoid subjecting their difference is probably one of degree rather
claims to the risk of falsification. In other than kind. Nevertheless, psychologists and
words, if findings corroborate the validity of a other mental health professionals need not
given Rorschach index, proponents can point wait for philosophers of science to solve the
to these findings as supportive evidence, but if demarcation problem to make use of the
these findings are negative, their proponents pseudoscience indicators delineated here to
can explain them away by maintaining that ascertain the validity of novel and untested
“clinicians never interpret this index in isola- claims.
tion anyway” (see Merlo & Barnett, 2001, for
an example). SEE ALSO: Clinical Science Model; Duhem–Quine
According to the “open concept” view Thesis; Hypothetico–Deductive Model; Meehl,
described above, these 10 warning signs do Paul E. (1920–2003); Popper, Karl (1902–94);
not exhaust the list of possible indicators of Science–Practice Gap; Scientific Metaphysics and
pseudoscience. To the contrary, they are only Ontology
a partial list of potential features of pseudo-
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