A User-Friendly Primer
* Pseudociencia Are disciplines that possess the superficial appearance of science but lack its substance. They do not play by the rules of science.
* Ej.: Phrenology, physiognomy, parapsychology, astrology, and subliminal persuasion for advertising purposes.
* “Junk Science” The intrusion of scientificallyunwarranted claims into the courtroom.
* “Research fields” and “Belief fields” to demarcate sciences from pseudosciences.
arguing that scientific practices are distinguished by research support as opposed to intuition or faith. For instance, subjective experience and intuition alone are insufficient for police officers to believe that their interrogation procedures produce accurate confessions;these procedures must be
validated by scientific evidence. Science and pseudoscience are not always easy to distinguish, because they probably fall at opposite ends of a continuum, differing in degree rather than in kind (Lilienfeld, 1999; Lilienfeld et al., 2003). Like many mental concepts, pseudoscience is probably an open concept (see Meehl, 1986) or “Roschian concept” (see Rosch, 1973; Rosch& Mervis,
1975), which is marked by indefinite boundaries, an indefinitely extendable list of indicators,
and an unclear inner nature. Moreover, Roschian concepts are characterized by a prototype
that embodies most or all features of the category. From this perspective, some disciplines
(e.g., astrology) embody most or all of the features of pseudoscience we will lay out in the
nextsection, whereas others (e.g., classical psychoanalysis; see Lack of Falsifiability and
Overuse of Ad Hoc Maneuvers section) embody some, but not all, of these features (see
Hines, 2003; Shermer, 2001, for discussions).
Note that this Roschian analysis does not imply that science and pseudoscience are
indistinguishable. As psychophysicist S. S. Stevens remarked, day and night shade into
eachother imperceptibly (hence the concepts of dusk and dawn), but that does not mean
that we cannot differentiate day from night (Leahey & Leahey, 1983). Differences in degree
can still be substantial and pragmatically meaningful, especially at the extremes of the
PSEUDOSCIENCE: KEY WARNING SIGNS
AND EXAMPLES FROM POLICE WORK
Indeed, a number of probabilistic indicators—which wecan think of as warning signs—
can help consumers of the literature to locate practices, including those in police work, on
the fuzzy spectrum between science and pseudoscience. Numerous authors have provided
varying lists of indicators that help to distinguish science from pseudoscience or “pathological
science” (e.g., Bunge, 1984; Coker, 2001; Langmuir & Hall, 1953; Lilienfeld, 1999;Lohr, Fowler, & Lilienfeld, 2002; Park, 2001; Ruscio, 2006).
Here, we focus on 10 such indicators that we believe to be especially pertinent to law
enforcement (see Table 1 for a summary of these indicators). Following each indicator, we
offer one example from police work. In evaluating this list, we should bear in mind that no
single indicator is either necessary or sufficient for thepresence of pseudoscience; some
developed sciences display one or more of these indicators, and some pseudosciences lack
one or more of them. Nevertheless, the more such indicators exhibited by a discipline, the
more suspicious of its claims we should become. Moreover, readers should bear in mind
that many of the examples we provide from police work probably fulfill multiple hallmarks
LACK OF FALSIFIABILITY AND OVERUSE OF AD HOC MANEUVERS
Philosopher of science Sir Karl Popper (1959) proposed that falsifiability is the central
criterion distinguishing science from nonscience. By falsifiability, Popper meant that scientific
claims could be demonstrated to be wrong if there were evidence contradicting
them. Such statements as “God created the universe” or “All humans...