This article has multiple issues. Please help improve it or discuss these issues on the talk page. (Learn how and when to remove these template messages)(Learn how and when to remove this template message)
Graphology is the analysis of the physical characteristics and patterns of handwriting purporting to be able to identify the writer, indicating psychological state at the time of writing, or evaluating personality characteristics. It is generally considered a pseudoscience. The term is sometimes incorrectly used to refer to forensic document examination.
Graphology has been controversial for more than a century. Although supporters point to the anecdotal evidence of positive testimonials as a reason to use it for personality evaluation, most empirical studies fail to show the validity claimed by its supporters.
- 1 Etymology
- 2 History
- 3 Status
- 4 Approaches
- 5 Vocabulary
- 6 Legal considerations
- 7 Applications
- 8 See also
- 9 References
- 10 Further reading
- 11 External links
Jean-Charles Gille stated in 1991 that Juan Huarte de San Juan's 1575 Examen de ingenios para las ciencias was the first book on handwriting analysis. In American graphology, Camillo Baldi's Trattato come da una lettera missiva si conoscano la natura e qualita dello scrittore is considered to be the first book.
Around 1830 Jean-Hippolyte Michon became interested in handwriting analysis. He published his findings shortly after founding Société Graphologique in 1871. The most prominent of his disciples was Jules Crépieux-Jamin who rapidly published a series of books that were soon published in other languages. Starting from Michon's integrative approach, Crépieux-Jamin founded a holistic approach to graphology.
Alfred Binet was convinced to conduct research into graphology from 1893 to 1907. He called it "the science of the future" despite rejection of his results by graphologists.
After World War I, interest in graphology continued to spread in Europe as well as the United States. In Germany during the 1920s, Ludwig Klages founded and published his finding in Zeitschrift für Menschenkunde (Journal for the Study of Mankind). His major contribution to the field can be found in Handschrift und Charakter.
In 1929 Milton Bunker founded The American Grapho Analysis Society teaching graphoanalysis. This organization and its system split the American graphology world in two. Students had to choose between graphoanalysis or holistic graphology. While hard data is lacking, anecdotal evidence indicates that 10% of the members of International Graphoanalysis Society (IGAS) were expelled between 1970 and 1980.
Although graphology had some support in the scientific community before the mid-twentieth century, more recent research rejects the validity of graphology as a tool to assess personality and job performance, and today it is considered to be a pseudoscience. Graphology is primarily used as a recruiting tool to screen candidates during the evaluation process. Many studies have been conducted to assess its effectiveness to predict personality and job performance. Recent studies testing the validity of using handwriting for predicting personality traits and job performance have been consistently negative.
In a 1987 study, graphologists were unable to predict scores on the Eysenck Personality Questionnaire using writing samples from the same people. In a 1988 study, graphologists were unable to predict scores on the Myers-Briggs test using writing samples from the same people. A 1982 meta-analysis drawn from over 200 studies concludes that graphologists were generally unable to predict any kind of personality trait on any personality test.
Measures of job performance appear similarly unrelated to the handwriting metrics of graphologists. Professional graphologists using handwriting analysis were just as ineffective as lay people at predicting performance in a 1989 study. A broad literature screen done by King and Koehler confirmed dozens of studies showing the geometric aspects of graphology (slant, slope, etc.) are essentially worthless predictors of job performance.
Rowan Bayne, a British psychologist who has written several studies on graphology, summarized his view of the appeal of graphology: "[i]t's very seductive because at a very crude level someone who is neat and well behaved tends to have neat handwriting", adding that the practice is "useless... absolutely hopeless". The British Psychological Society ranks graphology alongside astrology, giving them both "zero validity".
There is some evidence of a relationship between gender and handwriting style, though the correlation is weak.
Additional specific objections
- The Barnum effect (the tendency to interpret vague statements as specifically meaningful) and the Dr. Fox effect (the tendency for supposed experts to be validated based on likeability rather than actual skill) make it difficult to validate methods of personality testing. These phenomena describe the observation that individuals will give high accuracy ratings to descriptions of their personality that supposedly are tailored specifically for them, but are in fact vague and general enough to apply to a wide range of people. See, for example, Tallent (1958). Non-individualized graphological reports give credence to this criticism.
- Effect Size: Dean's (1992) primary argument against the use of graphology is that the effect size is too small. Regardless of the validity of handwriting analysis, the research results imply that it is not applicable for any specific individual, but may be applicable to a group.
- Vagueness: Some important principles of graphology are vague enough to allow a lot of room for a graphologist to skew interpretations to suit a subject or preconceived conclusion. For example, one of the main concepts in the theory of Ludwig Klages is form-niveau (or form-level): the overall level of originality, beauty, harmony, style, etc. of a person's handwriting—a quality that, according to Klages, can be perceived but not measured. According to this theory, the same sign has a positive or negative meaning depending on the subject's overall character and personality as revealed by the form-niveau. In practice, this can lead the graphologist to interpret signs positively or negatively depending on whether the subject has high or low social status.
Systems of handwriting analysis
|This section may rely excessively on sources too closely associated with the subject, potentially preventing the article from being verifiable and neutral. (October 2014) (Learn how and when to remove this template message)|
Each approach to handwriting analysis has spawned several systems.
Integrative graphology focuses on strokes and their relation to personality. Graphoanalysis was the most influential system in the United States, between 1929 and 2000. The Sistema de Xandró is another method of integrative graphology. Holistic graphology is based on form, movement, and use of space. The psychogram is another method which uses specific diagrams to analyze handwriting. The Personal Worth Chart is one such method developed by the Handwriting Consultants of San Diego during the early 1980s. The psychograph is an additional psychogram method. was developed by Leslie King during the 1970s .The Wittlich Character Diagram, and the Muller-Enskat Protokol are other psychogram methods.
Four academic institutions offer an accredited degree in handwriting analysis:
- The University of Urbino, Italy: MA (Graphology)
- Instituto Superior Emerson, Buenos Aires, Argentina: BA (Graphology)
- Centro de Estudios Superiores (CES), Buenos Aires, Argentina: BA (Graphology)
- Autonomous University of Barcelona, Barcelona, Spain: MA (Graphology)
The majority of material in the field is oriented toward the Latin writing system. Courses offered in the subject reflect that bias.
Every system of handwriting analysis has its own vocabulary. Even though two or more systems may share the same words, the meanings of those words may be different. The technical meaning of a word used by a handwriting analyst, and the common meaning is not congruent. Resentment, for example, in common usage, means to feel or exhibit annoyance. In Graphoanalysis, the term indicates a fear of imposition.
A report by the Hungarian Parliamentary Commissioner for Data Protection and Freedom of Information says that handwriting analysis without informed consent is a privacy violation.
In the United States
Gender and handwriting
There have been a number of studies on gender and handwriting. Uniformly the research indicates that gender can be determined at a significant level. The published studies on ethnicity, race, age, nationality, gender orientation, weight, and their relationship to handwriting have had mixed results.
Americans with Disabilities Act of 1990
One of the rules of thumb in human resources is that if an individual who has an ADA-defined disability cannot take a test, then nobody can. As a result, tests that cannot be adapted for use by those individuals will not be used by a company.
Handwriting clearly falls into the group of tests that cannot be adapted to be administered to individuals who fall within one or more ADA-defined disabilities. Blind people, for example, do not develop the required fluency in handwriting, for the writing to be correctly analyzed.
Questions that handwriting analysts ask before doing an analysis can be illegal under this act.
Graphology in court testimony
In Carroll v. State [276 Ark 160; 634 SW 2d 99, 101-102 (1982)] the opposing handwriting analysts showed unprofessionalism.
A company takes a writing sample provided by an applicant, and proceeds to do a personality profile, matching the congruency of the applicant with the ideal psychological profile of employees in the position.
A graphological report is meant to be used in conjunction with other tools, such as comprehensive background checks, practical demonstration or record of work skills. Graphology supporters state that it can complement but not replace traditional hiring tools.
Research in employment suitability has ranged from complete failure to guarded success. The most substantial reason for not using handwriting analysis in the employment process is the absence of evidence of a direct link between handwriting analysis and various measures of job performance.
Graphology has been used clinically by European counselors and psychotherapists. When it is used, it is generally used alongside other projective personality assessment tools, and not in isolation. It is often used within individual psychotherapy, marital counseling, or vocational counseling.
In its simplest form only sexual expression and sexual response are examined. At its most complex, every aspect of an individual is examined for how it affects the other individual(s) within the relationship. The theory is that after knowing and understanding how each individual in the relationship differs from every other individual in the relationship, the resulting marriage will be more enduring.
Medical graphology is probably the most controversial branch of handwriting analysis. Strictly speaking, such research is not graphology as described throughout this article but an examination of factors pertaining to motor control. Research studies have been conducted in which a detailed examination of handwriting factors, particularly timing, fluidity, pressure, and consistency of size, form, speed, and pressure are considered in the process of evaluating patients and their response to pharmacological therapeutic agents. The study of these phenomena is a by-product of researchers investigating motor control processes and the interaction of nervous, anatomical, and biomechanical systems of the body.
The Vanguard Code of Ethical Practice, amongst others, prohibits medical diagnosis by those not licensed to do diagnosis in the state in which they practice.
||This section needs more medical references for verification or relies too heavily on primary sources. (October 2014)|
This is the practice of changing a person's handwriting with the goal of changing features of his or her personality. It originated in France during the 1930s, spreading to the United States in the late 1950s. The purported therapy consists of a series of exercises which are similar to those taught in basic calligraphy courses, sometimes in conjunction with music or positive self-talk.
Systems of handwriting analysis
- Asemic writing
- Questioned document examination
- List of topics characterized as pseudoscience
- Longman Dictionary of Psychology and Psychiatry, Longman Group United Kingdom, 1983
- Nevo, B Scientific Aspects Of Graphology: A Handbook Springfield, IL: Thomas: 1986
- "Barry Beyerstein Q&A". Ask the Scientists. Scientific American Frontiers. Retrieved 2008-02-22. "they simply interpret the way we form these various features on the page in much the same way ancient oracles interpreted the entrails of oxen or smoke in the air. i.e., it's a kind of magical divination or fortune telling where 'like begets like'".
- Graphology, on season 8 , episode 2 of Scientific American Frontiers.
- James, Barry (3 August 1993). "Graphology Is Serious Business in France : You Are What You Write?". New York Times. Retrieved 18 September 2010.
- Driver, Russel H.; Buckley, M. Ronald; Frink, Dwight D. (April 1996), "Should We Write Off Graphology?", International Journal of Selection and Assessment, Blackwell Publishing Ltd, 4 (2): 78–86, doi:10.1111/j.1468-2389.1996.tb00062.x, ISSN 1468-2389.
- Furnham, Adrian; Barrie Gunter (1987), "Graphology and Personality: Another Failure to Validate Graphological Analysis.", Personality and Individual Differences, 8 (3): 433–435, doi:10.1016/0191-8869(87)90045-6.
- "Fine Dictionary". Retrieved 2014-09-22.
- Gille-Maisani, Jean Charles(1991): Psicología de la Escritura (Psychology of the Handwriting), Barcelona, Herder. Prefaced by Augusto Vels
- Examen de ingenios para las ciencias.
- Roman, Klara G. (1952), Handwriting: A Key to Personality (1st ed.), New York: Pantheon Books
- Baldi, Camillo (1622), Trattato come de una lettera missiva si conoscano la natura e qualita dello scrittore, Carpi: Girolamo Vaschieri, p. 54
- Michon, Jean-Hippolyte (1872), Le mystéres de l'écriture, Paris
- Michon, Jean-Hippolyte (1875), Systéme de graphologie, Paris
- Crépieux-Jamin, Jules, Traité pratique de graphologie, étude du caractère de l'homme d'après son écriture, Paris
- Crépieux-Jamin, Jules, L'écriture et le caractère, Paris: 1888
- Crépieux-Jamin, Jules, Handwriting and Expression (First English Translation ed.), London: 1892
- Crépieux-Jamin, Jules (1906), Praktisches Lehrbuch der Graphologie (Fifth German ed.), Leipzig: List
- Klages, Ludwig, Handschrift und Charakter, 1916
- Klages, Ludwig (1940), Handschrift und Charakter: gemeinverständlicher Abriss der graphologischen Technik (17th ed.), Barth, p. 256
- Lewinson, Thea Stein; Zubin, J (1942), Handwriting analysis; a series of scales for evaluating the dynamic aspects of handwriting (1st ed.), New York: King's Crown Press, pp. 147 + xiii
- Chimera, Mary Ann, Impact Magazine (5). Missing or empty
- Roy N. King; Derek J. Koehler (2000), "Illusory Correlations in Graphological Inference", Journal of Experimental Psychology: Applied, 6 (4): 336–348, doi:10.1037/1076-898X.6.4.336.
- Lockowandte, Oskar (1976), "Lockowandte, Oskar Present status of the investigation of handwriting psychology as a diagnostic method", Catalog of Selected Documents in Psychology (6): 4–5.
- Goodwin CJ (2010). Research In Psychology: Methods and Design. John Wiley & Sons. p. 36. ISBN 978-0-470-52278-3.
- Bayne, R., & O'Neill, F. (1988), "Handwriting and personality: A test of some expert graphologists' judgments", Guidance and Assessment Review (4): 1–3.
- Jennings, D. L., Amabile, T. M., and Ross, L. (1982), Informal covariation assessment: Data-based versus theory-based judgments. In D. Kahneman, P. Slovic, & A. Tversky (Eds.), Judgment under uncertainty: Heuristics and biases, Cambridge, England: Cambridge University Press, pp. 211–238
- Neter, E., & Ben-Shakhar, G. (1989), "The predictive validity of graphological influences: A meta-analytic approach", Personality and Individual Differences, 10 (10): 737–745, doi:10.1016/0191-8869(89)90120-7.
- Duffy, Jonathan; Giles Wilson (2005-02-01). "Writing wrongs". BBC News Magazine. Retrieved 2008-06-24.
- on YouTube
- Hartley, James, "Sex Differences in Handwriting: a comment on Spear", British Educational Research Journal, 17 (2): 141–145, doi:10.1080/0141192910170204
- Ware, J. E.; Williams, R. G. (February 1975), "The Dr. Fox effect: a study of lecturer effectiveness and ratings of instruction", Journal Medical Education, 50 (2): 149–156, doi:10.1097/00001888-197502000-00006, PMID 1120118
- Tallent, N (1958), "On Individualizing the Psychologists's Clinical Evaluation", Journal of Clinical Psychology, 14 (3): 243–244, doi:10.1002/1097-4679(195807)14:3<243::AID-JCLP2270140307>3.0.CO;2-A.
- Dean, Geoffrey A., "The Bottom Line: Effect Size", In Beyerstein & Beyerstein (1992): 269–341
- Beyerstein, Barry L.; Beyerstein, Dale F. (1992), The Write Stuff: Evaluation of Graphology - The Study of handwriting Analysis (1st ed.), Buffalo, NY: Prometheus Books, ISBN 0-87975-612-8
- Ulfried Geuter, The Professionalization of Psychology in Nazi Germany, pp. 95–96. Cambridge University Press, 1992.
- Pulver, Max Albert Eugen (1931), Symbolik der Handschrift (1st ed.), Zurich & Leipzig: Orell Füssli
- Pulver, Max Albert Eugen (1972), Symbolik der Handschrift (New ed.), Munich: Kindler, ISBN 3-463-18087-1
- Pulver, Max Albert Eugen (1944), Person, Charakter, Schicksal (1st ed.), Zurich: Orell Füssli
- Pulver, Max Albert Eugen (1949), Der Intelligenzausdruck in der Handschrift (1st ed.), Zurich: Orell Füssli
- Carter, Molly. "Handwriting Analysis and the Secrets of Graphology". Sciences 360. Helium, Inc. Retrieved 2014-09-22.
- Xandró, Mauricio (1949), Psicologia y Grafologia, Havana: Ed de Conf y Ensayos
- Xandró, Mauricio (1954), Abecedario Grafológico, Onate: Aránzazu
- Xandró, Mauricio (1955), Grafología Tratado de Iniciación, Barcelona: Stadium
- Cole, Charlie; Jean Hartman, Karey Starmer (1961–1968), Handwriting Analysis Workshop Unlimited: Professional Graphology Course, Campbell, CA: E C F Cole / HAWU
- Anthony, Daniel S. (1983) , The Graphological Psychogram: Psychological meanings of its Sectors; Symbolic Interpretation of its Graphic Indicators (Revised ed.), Fort Lauderdale, FL; New York NY
- Sassi, Paula; Whiting, Eldene (1983), Personal Worth Intermediate Course in Handwriting Analysis (1st ed.), San Diego, CA: Handwriting Consultants of San Diego
- King, Leslie W. (1978), Graphology Handbook for Tyros or Pros ... (1st ed.), Bountiful, UT: Handwriting Consultants of Utah
- Wittlich, Bernhard (1956), Graphologische Charakterdiagramme (1st ed.), Munich: Johann Ambrosius Barth
- Wittlich, Bernhard (1951), Angewandte Graphologi (2nd ed.), Berlin: Walter de Griyter & Co
- Müller, Wilhelm H.; Enskat, Alice (1973), Graphologische Diagnostik (20th ed.), Bern, Stuttgart, Wien: Verlag Hans Huber, ISBN 3-456-30514-1
- Müller, Wilhelm H. (1943), Mensch und Handschrift. Lehrbuch der Graphologischen Deutungstechnik zum Selbstunterricht (1st ed.), Bern: Munz
- Moretti, Girolamo Maria (1942), Trattato Scientifico di Perizie Grafiche su base Grafologica, Verona: L'Alberto
- Moretti, Girolamo Maria (1963), ISanti dalla scrittura: esami grafologici, Padova: Messaggero di S Antonio
- :Moretti, Girolamo (1980) : Trattato di Grafologia. Intelligenza – Sentimento, Padova, Ed. Messagero di S. Antonio, 12ª Ed.
- : Vels, Augusto: Tratado de Grafología, Barcelona, Editorial Vives, 1945
- :Vels, Augusto: El lenguaje de la Escritura, Barcelona, Editorial Miracle, 1949.
- :Vels, Augusto: Cómo ser importante, Barcelona, P.E.A.P., 1957.
- : Vels, Augusto: Escritura y Personalidad, Barcelona, Editorial Herder, 468 pág. - 8ª ed.
- :Vels, Augusto: La Selección de Personal y el problema humano en las empresas, Barcelona, Ed. Herder, 640 pág. -5ª ed.
- :Vels, Augusto: Diccionario de Grafología y términos psicológicos afines, Barcelona, Ed. Herder,1998, 532 pág., 5ª ed.
- :Vels, Augusto: Manual de Grafoanálisis, Barcelona, Ed. Herder, 264 pág., 2ª ed. revisada.
- :Vels, Augusto: Grafología Estructural y Dinámica, Barcelona, Ed. Herder, 404 pág.1997
- :Vels, Augusto: Grafología de la A a la Z, Barcelona, Ed. Herder, 2000,432 pág.
- Instituto Superior Emerson
- Centro de Estudios Superiores
- IGAS Department of Instruction (1964), The Encyclopedic Dictionary for Graphoanalysts (1st ed.), Chicago, IL: International Graphoanalysis Society
- IGAS Department of Instruction (1984), The Encyclopedic Dictionary for Graphoanalysts (3rd ed.), Chicago, IL: International Graphoanalysis Society
- Péterfalvi, Attila (16 March 2004). "Overview of the Data Protection Commissioner's investigation into the tender for the notary position of the city of Nagymaros". Hungarian Parliamentary Commissioner for Data Protection and Freedom of Information. Retrieved 2008-06-21.
- Binet, Alfred L. (1904), "La graphologie et ses révélations sur le sexe, l'âge et l'intelligence", L'Année Psychologique, 10: 179–210, doi:10.3406/psy.1903.3547
- Binet, Alfred L. (1902/1903), "Le sexe de l'écriture", Année Psychologique, 9: 17–34 Check date values in:
- Young, P. T. (1931), "Sex differences in Handwriting", Journal of Applied Psychology, 15 (5): 486–498, doi:10.1037/h0072627
- Wittlich, Bernhard (1927), "Ein Betrag zur Grage der Geschlechtsbestimmung nach der Handschrift", Zeitschrift fűr Menschenkenntnis, 3: 42–45
- Geyer, L. (1929), Beitäge zur Graphologischen Technik. Derinnere Widerstreit der Bewusstseinsformen(Rassen), Kraftschwerpunkte (Naturelle) sowie Volksschichten als Urasache jeder unrhythmischen schwankungsbreite sämtl. Scrhiftelemente: Eine Lösung, Heidelberg: Selbstverlag
- Krieger, P. L. (1935), "Artmerkmale an ausländischen Handschriftenproben unter rassenseelenkundlichen Gesichtspunkt", Zentralblatt für Graphologie, 6: 95–105
- Krieger, P. L. (1937), "Rhythmus and Schreibinnervation bei Jugendlichen und Erwachsenen", Zeitschrift für pädaagogische Psychologie und Jugendkunde, 38: 15–31
- Garth, T. R. (1931), "The Handwriting of Indians", Journal of Educational Psychology, 22 (9): 705–719, doi:10.1037/h0071730
- Garth, T. R.; Mitchell, J J; Anthony, C. N. (1939), "The Handwriting of Negroes", Journal of Educational Psychology, 30: 69–73, doi:10.1037/h0063156
- Weisser, E. A. (1932), "A Diagnostic Study of Indian handwriting", Journal of Educational Psychology, 23 (9): 703–707, doi:10.1037/h0075632
- Kollarits, J. (1933), "Űber Sprach- und Schreibstörungen in allgemeinen und als "kleine Zeichen der Geistesschwächung" bei Tuberkulose und im Alter. Das Verhaltnis zwischen innerer Sprache und Schreibfehler", Zeitschrift für die gesamte Neurologie und Psychiatrie, 99 (1): 109–196, doi:10.1007/BF01814310
- Binet, Alfred L., "L'âge et l'écriture", La Revue des Revues, 484 (4): 182–195;326–341
- Binet, Alfred L. (1904), "La Graphologie et Ses Révélations sur le sexe, l'âge et l'intelligence", L'Année Psychologique, 10: 179–210, doi:10.3406/psy.1903.3547
- Blumenthal, E. (1959), "Schulschriften der Verschiedenen Länder. Beihefte zur", Schweizerischen Zeitschrift für Psychologie undihre Anwendungen, 31: 3–116
- Johnston, Dianna B. (28 February 2001), Title VII: Disparate Impact, Handwriting Analysis, The U.S. Equal Employment Opportunity Commission, archived from the original on September 27, 2006, retrieved 2007-05-24
- Partial List of Characteristics Evaluated, Behavioral Profiling International, retrieved 2007-06-05[dead link]
- Lighton, R. E. (1934). "A Graphological Examination of the Handwriting of Air Pilots". Thesis in the Faculty of Arts. University of Pretoria.
- Luca, E. S. (1973), "Major Aptitudes and Personality Characteristics of 42 Dental Students as Evaluated Through Their Handwriting", New York Journal of Dentistry, 43: 281–283
- Thomas, Steven L.; Vaught, Steve (September 2001). "The write stuff: What the evidence says about using handwriting analysis in hiring". SAM Advanced Management Journal. 66 (4): 31–35.
- Koehn, Daryl. "Handwriting Analysis In Pre-Employment Screening". The Online Journal of Ethics. 1 (1).
- Spohn, Julie (Fall 1997). "The Legal Implications of Graphology". Washington University Law Quarterly. 73 (3).
- Poizner, Annette (2012). Clinical Graphology: An Interpretive Manual for Mental Health Practitioners. Springfield, IL: Charles C Thomas Publishers
- Karohs, Erika (1994) SSS. Pebble Beach, CA
- IGAS (1976) MGA. Chicago, IL: IGAS
- Ludewig, R.; Lewinson, T. S.; Lewinson, T. S. (1992), "Profiles and Limits of Medical Graphology", Z Gesamte Inn Med, 47 (12): 549–557, PMID 1285461.
- Kopp, W.; Paulson, G.; Allen, J.; Smeltzer, F.; Brown, F.; Koss, W. (1970), "Parkinson's Disease: L-dopa Treatment and Handwriting Areas", Current Therapeutic Research, 12 (3): 115–124.
- de Sainte Columbe (1966), Grapho Therapeutics: Pen and Pencil Therapy (1st ed.), Hollywood, CA: Laurida Books
- de Sainte Columbe, Paul (1972), Grapho Therapeutics: Pen and Pencil Therapy (2nd ed.), Hollywood, CA: Paul de St Columbe Center
- Bangerter A, König CJ, Blatti S, Salvisberg A (2009). "How Widespread is Graphology in Personnel Selection Practice? A case study of a job market myth". International Journal of Selection and Assessment. 17 (2): 219–230. doi:10.1111/j.1468-2389.2009.00464.x.
- Berger J (2002). Shermer M, ed. Handwriting Analysis and Graphology. The Skeptic Encyclopedia of Pseudoscience. ABC-CLIO. pp. 116–120. ISBN 978-1-57607-653-8.