When a crime is committed, the police gather and secure evidence. If we were to appear in court, standing accused of that crime, and we were not presented with sufficient proof, we would likely conclude that our rights had been violated. We rely on evidence when we sit down on a roller coaster. We trust that the engineers gathered enough evidence on the durability of the particular materials used in its construction. We also trust that the doctor treating us is applying evidence-based methods, and if this were not the case, we’d probably get quite angry with him/her. Why is it that in so many situations we seek out evidence and rely on it?

Likely because evidence-based actions deliver good results. Evidence-based medicine led to a significant increase in humans’ average lifespan in the twentieth century, and diseases which were fatal just a few decades earlier are today a far lesser threat. The development of technology we are both witnesses to and beneficiaries of is possible only because of serious consideration being given to evidence. On the other hand, actions undertaken without evidence or in which evidence is given insufficient consideration frequently end in disaster, or even tragedy. Are we, however, rational enough to seek out in every sphere of activity evidence that would serve to guarantee our effectiveness? Do we ask the teachers teaching our children for evidence? Are their methods based on evidence? How much weight do managers responsible for managing people give to evidence? Or trainers in charge of training our employees? As it is, the answer here is far less than clear. Many methods of teaching or management are based on evidence, but many of them are simply “common wisdom,” or long-standing myths that can do more harm than good. Why, then, do we depend solely on evidence in some areas, while in others we do not?

We can identify two main causes of this phenomenon:

• The first—the application of ineffective methods in teaching or management rarely leads to spectacular catastrophes. The negative effects consist in insignificant wasting of time at trainings, but frequently for a large number of people. This is also an inefficient use of financial resources, but almost never of such sums that would threaten the company.

• The second cause results directly from the first. Because the failures that derive from the application of ineffective methods are never spectacular, we have become accustomed to adopting a very tolerant approach to evidence, and we frequently accept subjective experiences as evidence. We demand that an engineer present us with hard calculations, but from training methods we often only require that they be attractive and appealing to their participants. Is this a rational approach? Shouldn’t we ask about evidence with greater frequency? Shouldn’t we look for the most effective methods? The question is, however, how should we do so?

Most importantly, we should know that almost anything can constitute evidence. The testimony of an eyewitness who has seen a UFO can be evidence confirming the existence of extraterrestrials. In turn, a picture of someone wandering around the mountains can become evidence of the existence of beings referred to as Yeti. The recommendations of patients can be evidence of the effectiveness of a doctor, while the value of training and developmental methods can be attested to in the opinions of participants. We can identify many such kinds of evidence, but scientists do not treat them as decisive; indeed, the essence of evidence-based practices is the search for the best available evidence, and not just any evidence at all. Here, however, another question arises that may seem a difficult one at first glance: how can we determine whether a given piece of evidence is of greater or lesser value? How to orient oneself in the thicket of methods and means of distinguishing which piece of evidence is worthy of trust? Thankfully, we are aided by scientists, who have wondered for decades about which proofs should be given the greatest weight, and which should be approached with caution. We can be aided in this respect by the broadly respected hierarchy of evidence (e.g., Ng & Benedetto, 2016; Page & Meerabeau, 2004; Petrisor & Bhandari, 2007). Despite minor differences among authors, the majority of them admit that the evidence we cite is at the bottom of the hierarchy. The majority of scientists also agree with the statement that the highest level is occupied by umbrella reviews, meta-analyses, and systematic reviews. One rung lower are randomised controlled trials, and lower still are quasi-randomised trials and observational studies.

Desiring to act rationally, whether in making a decision about a training seminar, or in selecting a management method, we should always examine on what level of the hierarchy of evidence are the proofs we are using to justify our actions. Basing one’s actions on evidence lower in the hierarchy when there is evidence of greater significance available to us brings to mind an old Indian tale of blind men who decide to learn about an elephant. One of them, upon touching the elephant’s hard skin, said it was a wall. The second touched a tusk, and said it was a spear. The third, having touched the elephant’s trunk, was convinced he had encountered a sort of snake. The fourth, brushing up against the elephant’s knee, said it was a tree. Having felt a gust of wind caused by the elephant’s breathing, the fifth blind man called it a fan. And, finally, the sixth, having grabbed the elephant by its tail, said that it was just a normal piece of rope.

The evidence-based approach was developed in places where opinions and viewpoints can have no truck—in saving human lives, in the work of engineers. It has proven itself, which is why thinking managers employ it in managing, good teachers in teaching, and good trainers in trainings. There is also increasingly frequent mention of evidence-based politics. We recommend this approach to all practitioners, which is why we have performed an analysis of the available evidence regarding the effectiveness of neurolinguistic programming that can serve as an aid in taking decisions about using it for one’s own development, as well as for needs related to employee training.

In the 1970s, Richard W. Bandler and John Grinder had the idea to create a practical therapy model. They reasoned that a group of recognised psychotherapists acted on the basis of implicit theories that helped them achieve substantial psychotherapeutic effectiveness and great rapport with clients. Grinder and Bandler concluded that careful observation of these skillful therapists at work should lead to the identification of successful patterns of practice that would then be empirically verified and disseminated to other practitioners. For several years, they observed such therapists as Fritz Perls, Milton H. Erickson, and Virginia Satir at work. Based on these observations and reflections, Grinder and Bandler formulated neuro-linguistics programme’s (NLP’s) tenets and hypotheses. With time, their strategy was promoted as a “science of excellence.” It reflected a procedure also known as “modelling,” in which one studies the performance of highly successful people from different walks of life in order to learn skills to improve one’s own personal and professional life (O’Connor & Seymour, 1993).

The originators of NLP described it as a “model” rather than a “theory.” The central philosophy of the NLP model is summed up in the phrase “the map is not the territory” (e.g., Lankton, 1980, p. 7). The idea is that each individual operates on the basis of his or her internal representation of the world (the “map”) and not the world itself (the “territory”). One’s interactions with the world are formed by mental maps created from one’s surroundings. The maps are by nature distorted, limited, and inflexible. The task of the therapist is to understand the client’s particular map and to convey that understanding to the client. As Heap (2008) and Newbrook (2008) maintained, this philosophy was verbalised by the philosopher and linguist Korzybski (1933).

At the core of NLP lies the notion of a preferred representational system (PRS). It is argued that the maps people make of their world are represented by five senses: visual, kinaesthetic (referring to both tactical and visceral sensations), auditory, olfactory, and gustatory. Every experience is composed of information received through these sensory systems. NLP proponents coined the term “representational systems” to describe the patterns in the way that sensory data are represented in people’s minds (Bandler & Grinder, 1979; Grinder & Bandler, 1976). They claimed that every person processes most information using predominantly one PRS.

Another ostensible discovery of which NLP originators were particularly proud was the idea that access to the representational systems is possible through so-called accessing cues, and more specifically, through eye movements (EMs). They explained, for instance, that a person engaged in a cognitive activity in the visual mode would tend to look upwards, whereas a person using the auditory model would tend to look horizontally (Bandler & Grinder, 1979). The kinaesthetic mode is believed to be associated with a gaze downwards to the right. Thus, careful observation of such EMs should enable an NLP therapist to unequivocally identify the PRS of a client or an interlocutor and, as a consequence, facilitate a therapeutic intervention matched to the individual’s particular PRS.

The final assertion is that by matching, mirroring, or pacing clients’ verbal and non-verbal behaviour, including their PRS, the NLP practitioner has the opportunity to achieve effective communication, gain the client’s trust, and enhance rapport. Reflecting on the example of model therapists, in order to work effectively with a client, the therapist should strive to match the client’s PRS to be able to use his or her “map.” A trained practitioner can identify the method in which information is stored through careful observation of the client’s eye-gaze patterns, posture, breathing patterns, tone of voice, and language patterns. Subsequently, the therapist takes every care to match the clients’ PRS while communicating with them. PRS matching effected through following the same language patterns—i.e., by using predicates typical of the mode operated by the client—ostensibly yields the best results in facilitating communication and enhancing therapeutic effectiveness.

The NLP originators promoted it as a sensationally effective and rapid form of psychological therapy. They claimed that NLP helped overcome such problems as phobias and learning disabilities in less than an hour’s session, whereas with other therapies, progress might take weeks or months (e.g., Bandler & Grinder, 1979, p. ii; Lankton, 1980, pp. 9–13). They also maintained that a single session of NLP combined with hypnosis could eliminate certain eyesight problems, such as myopia (Grinder & Bandler, 1981, p. 166), and even cure the common cold (Grinder & Bandler, 1981, p. 174). Today, we can find similarly alluring promises in many NLP programmes and advertisements.

The development of NLP can be analysed in terms of a particular research paradigm within social psychology known as the “full cycle” approach, developed by Cialdini (1980). Cialdini critically argued that experimental lab-based research, although offering the opportunity to control variables and establish causality, had several accompanying weaknesses. The most prominent was the inability to determine the strength or prevalence of phenomena in the natural environment. Cialdini argued instead that researchers should use naturalistic observation to determine the presence of an effect in the real world, then develop a theory to determine what processes may underlie the effect, followed by experimentation to verify the effect and its underlying processes, and finally return to the natural environment to corroborate the experimental findings.

Bandler and Grinder omitted the critical stage of empirical verification of their assertions. They found that part of the process redundant and unnecessary, and so moved directly to the formulation of the model and to putting it into practice. They were known for their openly demonstrated contempt for the scientific verification of NLP hypotheses:

As far as I can tell, there is no research to substantiate the idea that there is eyedness. You won’t find any research that is going to hold up. Even if there were, I still don’t know how it would be relevant to the process of interpersonal communication, so to me it’s not a very interesting question. (Bandler & Grinder, 1979, p. 31)

Nevertheless, many subsequent researchers did subject NLP to empirical evaluation.

Beginning in the 1980s, a wide range of articles on NLP were published. Particular attention should be paid to several reviews of research on the effectiveness of NLP. The first two were conducted by Sharpley (1984, 1987). In his first analysis, he reviewed 15 studies examining the possibility of identifying and matching clients’ PRS. Sharpley (1984) concluded that “the identification of this PRS (if it is a PRS and not merely current language style) by either eye movements or self-report is not supported by the research data … The existence or stability of the PRS is irrelevant to predicate matching as a counselling process, and parsimony argues for the process rather than the yet unverified theory … Of most importance, there are no data reported to date to show that NLP can help clients change” (p. 247).

The second review (Sharpley, 1987) is even more conclusive. It was written as a response to a critical paper by Einspruch and Forman (1988), who analysed 39 studies on NLP and described methodological errors and a lack of sufficient knowledge about the theoretical underpinnings of NLP demonstrated by authors. Sharpley took into account works investigated by Einspruch and Forman and expanded that sample with additional ones to perform an analysis of 44 studies. Six papers (13.6%) provided evidence supportive of NLP-derived theses, 27 (61.4%) failed to lend support for one or more of those tenets, and 11 (25%) showed only partial support. Sharpley examined all works available, starting from doctoral dissertations to papers published in high-ranking peer-reviewed journals. He summed up his review as follows:

There are conclusive data from research on NLP, and the conclusion is that the principles and procedures suggested by NLP have failed to be supported by those data … Certainly research data do not support the rather extreme claims that proponents of NLP have made as to the validity of its principles or the novelty of its procedures. (pp. 105–106)

There are also other important research reviews. In 1988, Heap analysed 63 studies and concluded that the assertions of NLP writers concerning representational systems had been objectively investigated and found to be wanting. The hypothesis that it is possible to identify PRS through careful observation of EMs was likewise not confirmed. In Heap’s view, the stated conclusions and the failure of investigators to demonstrate convincingly the alleged benefits of predicate matching seriously questioned the role of such procedures in counselling. Dorn, Brunson, Bradfor, and Atwater (1983) similarly concluded from their review that there was no demonstrably reliable method of assessing the hypothesised PRS.

If the NLP assertion of a reliably identifiable PRS and the corresponding ability to enhance communication through PRS matching proved to be true, it would have important implications for neuroscience, cognitive psychology, and a number of other disciplines. If the NLP claims concerning its instant effectiveness proved to be true, the field of psychotherapy would be transformed, perhaps even revolutionised, and research reporting the effectiveness of therapy would position NLP as a potential first-rate therapy. Nothing of the sort has taken place. Instead, experts warn against using NLP, and classify it is as one of many dubious “fringe therapies” (Beyerstein, 2001) or “power therapies” (Devilly, 2005). NLP is also found on many lists of discredited therapies. Norcross, Koocher, and Garofalo (2006) sought to establish consensus on discredited psychological treatments and assessments using the Delphi methodology. A panel of 101 experts participated in a two-stage survey, wherein they had to report familiarity with 59 treatments and 30 assessment techniques and rate them on a continuum from not at all discredited (1) to certainly discredited (5). Neurolinguistic Programming for treatment of mental/behavioural disorders was assessed at an average of 3.87 (SD = 0.92). For comparison, “angel therapy for treatment of mental/behavioral disorders” obtained the highest score, M = 4.98 (SD = 0.14), and “behavior therapy for sex offenders” obtained the lowest, M = 2.05 (SD = 0.91).

Similarly, Roderique-Davies (2009) cautioned against applying NLP to therapeutic practice in an article Neuro-linguistic programming: Cargo cult psychology? in which he concluded:

NLP masquerades as a legitimate form of psychotherapy, makes unsubstantiated claims about how humans think and behave, purports to encourage research in a vain attempt to gain credibility, yet fails to provide evidence that it actually works. (p. 62)

The Army Research Institute (ARI) asked the National Research Council to assess the credibility of “New Age” techniques, including NLP, considered for implementation by the US Army with a view to enhancing human performance. The committee in charge of the review also challenged the effectiveness of NLP. They concluded:

The conclusion was that little if any evidence exists either to support NLP’s assumptions or to indicate that it is effective as a strategy for social influence. (Swets & Bjork, 1990, p. 90)

Von Bergen, Soper, Rosenthal, and Wilkinson (1997) analysed areas of application of “alternative training techniques” in human resources management, and likewise concluded:

We identified four alternative training techniques that have been widely touted and sold to government and industry: subliminal stimulation, mental practice, meditation, and NLP. Finding that the claims made for three of these techniques, mental practice being the exception, did not stand up to scientific scrutiny, we encourage HRD professionals to guard against substituting testimonials and popularity in the marketplace for research evidence when they consider a new training aid. (p. 291)

An evaluation of the effectiveness of NLP as a communication theory and its contribution to clinical practice and family therapy is similarly unflattering:

The academic verdict on NLP is given: NLP’s theory of the person cannot account for the wide range of intrapsychic and interpersonal problems encountered in clinical practice. A final verdict is withheld until further clinical studies and experimental investigations are reported. (Baddeley, 1989, p. 73)

In 2010, another review of research on NLP was published (Witkowski, 2010). It presented the concept of NLP in the light of empirical research in the Neuro-Linguistic Programming Research Data Base. From among 315 articles, the author selected 63 studies published in journals from the Master Journal List of ISI. Out of 33 empirical studies, 18.2% show results supporting the tenets of NLP, 54.5% results non-supportive of the NLP tenets, and 27.3% report uncertain results. The qualitative analysis indicates the greater weight of the non-supportive studies and their greater methodological worth against the ones supporting the tenets. Analysis results contradict the claim of empirical bases of NLP.

Two years later, a systematic research review was published (Witkowski, 2012). In order to examine the scientific status of NLP, 401 publications were identified, including a subsample (n = 66) that was published in prestigious journals. Of the entire sample, 21 methodologically sound empirical studies published since the last comprehensive reviews of NLP were identified (Heap, 1988; Sharpley, 1984, 1987). Of these studies, 9.5% were found to be generally supportive of the tenets of NLP and/or the effectiveness of NLP techniques, 19% were partially supportive, and 71.5% were non-supportive. The author concluded his review:

NLP is ineffective both as a model explaining human cognition and communication, and as a set of techniques of influence and persuasion. (p. 37)

Also in 2012, Sturt with her co-workers published a systematic review of the effects of NLP on health outcomes. To evaluate these effects the researchers searched: MEDLINE^®, PsycINFO, ASSIA, AMED, CINAHL^®, Web of Knowledge, CENTRAL, NLP specialist databases, reference lists, review articles, and NLP professional associations, training providers, and research groups. Their searches revealed 1,459 titles from which ten experimental studies were included into the review. Five studies were randomised controlled trials (RCTs), and five were pre-post studies. Targeted health conditions were anxiety disorders, weight maintenance, morning sickness, substance misuse, and claustrophobia during MRI scanning. NLP interventions were mainly delivered across 4–20 sessions, although three were single-session. Eighteen outcomes were reported, and the RCT sample sizes ranged from 22 to 106. Four RCTs reported no significant between-group differences, with the fifth finding in favour of the NLP arm. Three RCTs and five pre-post studies reported within-group improvements. The authors concluded that there is little evidence that NLP interventions improve health-related outcomes. In their opinion, there was insufficient evidence to support the allocation of National Health Service (NHS) resources to NLP activities outside of research purposes (Sturt et al., 2012).

The only meta-analysis on NLP was published in 2015 (Zaharia, Reiner, & Schütz, 2015). The authors removed 350 from a total number of 425 studies, considering them not relevant based on the title and abstract. In the final analysis, they included 12 studies, with numbers of participants ranging between 12 and 115. The vast majority of studies were prospective-observational. The article evaluates the effectiveness of NLP therapy for individuals with social/psychological problems. The overall meta-analysis found that NLP therapy may add an overall standardised mean difference of 0.54, with a confidence interval of CI = [0.20; 0.88]. In the opinion of the authors, NLP as a psychotherapeutic modality shows results that can hold their ground in comparison with other psychotherapeutic methods.

As the results of this meta-analysis run contrary to the conclusions derived from former reviews, they must be taken into account very carefully. First of all, it is not quite clear how the researchers reduced the number of studies from 75 to 12. Although they write about excluding criteria such as “Not the right population; studies conducted on healthy individuals with social/psychological problems (n = 19); Not the right intervention (n = 17): studies conducted in healthy individuals with social/psychological problems (n = 8), depression (n = 5), other (n = 4); Not the good outcome: studies carried out in healthy individuals with social/psychological problems (n = 17); Excluded based on study design (n = 11): review, editorial, comment letter, study design protocol. (p. 357),” we are unable to see what studies were excluded. Moreover, the authors included into their sample also unpublished and never peer-reviewed data. Also of significance is that all authors of this article are active practitioners of NLP, which may give rise to conflicts of interest.

Today, after 40 years of research devoted to the concept, NLP is closer to the image of an unstable house built on sand rather than an edifice founded on empirically-based rock. In 1988, Heap passed verdict on NLP. As the title of his article indicated, this was an interim verdict. In his conclusions, he wrote:

If it turns out to be the case that these therapeutic procedures are indeed as rapid and powerful as is claimed, no one will rejoice more than the present author. If however these claims fare no better than the ones already investigated then the final verdict on NLP will be a harsh one indeed. (p. 276)

We are fully convinced that we have gathered enough evidence to announce this harsh verdict now, but before we do so, we would like to take a thorough look at the practice of NLP.

NLP is a collection of diverse methods and techniques that would be hard to call an obligatory canon. NLP practitioners in different countries use chosen methods in combination with their own inventions. We decided to describe and assess a few of the methods most frequently appearing in books on NLP and in training programmes. The selection is thus necessarily a subjective one, but it encompasses the most important offerings one can come across at NLP courses, in books, and in internet-based materials.

Empirical analysis of the primary assumptions underlying NLP demonstrates that they have no basis in fact. Theories about the existence of systems of representation and the possibility to discover them through analysis of EMs have not found confirmation in psychological studies. Other elements constituting the content of NLP courses, such as presuppositions, metamodel, anchors, metaprograms, and the Dilts Pyramid are either adapted scientific conceptions, or—more frequently—an idea without confirmation in systematic scientific studies. The same is true of other methods not discussed here, such as timelines, the Milton model, or reframing. Each of them features a mix of scientific and subjective content, and at times the weird ideas of authors and practitioners. NLP thus does not constitute a cohesive theory in which fundamental and verified assumptions lead to practical tips for users. It is rather a group of diverse and interesting-looking set of tools based on the subjective experience of users and dressed up in marketing mumbo jumbo. From the perspective of the evidence-based approach, we are looking at a less-than-credible proposition. The question thus arises: where does the popularity of this phenomenon come from?

First, NLP employs language that is attractive for the reader and the participant of development programmes. The term “neurolinguistic programming” suggest a strong grounding in neurobiology and linguistics. From the scientific perspective, all human actions are based in the activity of the nervous system, and are thus neuro. In this respect, NLP is no different from learning a foreign language, dance, eating with chopsticks, or any other activity. Placing the word “neuro” in the name gives it the veneer of science. Apart from the vague, and at times non-scientific considerations of Dilts about the foundation of his pyramid (see the section on the Dilts Pyramid), the creators of NLP do not address the activity of the human nervous system. Things are slightly different with the term “linguistic.” Indeed, NLP tools directly refer to language, and some of them (metamodel, presupposition) are associated with the science of linguistics or psycholinguistics. In turn, the word “programming” is clearly overused. NLP practitioners talk about programming the mind, which in the best case is simply exerting influence, frequently to dubious effect.

The second cause of the popularity of NLP is the promise of quick and spectacular effects. At NLP courses, and particularly in short films on the internet, we are told we will cope with negative emotions, achieve our goals, have better relations with people, get rid of our fears and other psychological problems, and generally attain a higher quality of life. The effectiveness of NLP techniques is promoted primarily by its practitioners and advocates. However, there is precious little by way of documented studies. An exception is one meta-analysis on the application of NLP techniques in psychotherapy (Zaharia et al., 2015).

The third cause is linked to the “discovery” of the secrets of the mind, hidden to the mere mortal human. For example, observing the movements of eyes, one can, according to Grinder and Bandler, understand whether a given situation is recalled or constructed. If constructed, this can mean that someone is lying. The promise of recognition of lies through observation of eyeball movements is exceptionally attractive.

All of these factors contribute to the popularity of NLP. However, from the scientific perspective, we are dealing with a well-promoted set of techniques which come in small part from science, and their remainder has either not been verified at all, or the results have come back negative.

As we wrote in the introduction, the essence of evidence-based practices is the search for not just any evidence, but the best available evidence. In this chapter we have presented the evidence available on both the fundamental theoretical assumptions of NLP and the effectiveness of methods applied, as well as those concerning particular techniques. The majority of available evidence from higher levels of the hierarchy indicates that both the assumptions of NLP and the methods and techniques applied within the approach find no confirmation in empirical science. In opposition to the evidence we have presented is evidence located lower in the hierarchy, that is, subjective experiences of particular practitioners of NLP. At the same time, qualitative analysis of NLP techniques indicates that there are more cohesive and tested methods we may draw on science for.

Managers and engineers seeking to retain an evidence-based approach in working with people, during training exercises, or as part of self-development initiatives should rather look to methods whose effectiveness has been confirmed in multiple studies. This will save them time, as well as provide them with greater effectiveness and coherence in their undertakings.

Some common characteristics of pseudoscientific approaches, which we consider NLP to be, allow practitioners to effectively identify them, and facilitate selecting the most effective. Pseudoscientific methods based on evidence low in the hierarchy or simply without any evidence in support most frequently:

1. promise rapid effects incongruent with those which are presently applied broadly;

2. are very frequently characterised as breakthrough methods in a given field of knowledge;

3. develop primarily outside of mainstream research in a given field, because science rather quickly establishes their usefulness and rejects them as unpromising;

4. explain the reluctance of scientists to engage them in terms of threat, conservatism, and the absence of sufficient competence to assess “innovative” methods;

5. as opposed to science, frequently have little or no roots in the past, which is visible in the lack of bibliographies in papers by their proponents;

6. create an internal jargon that is frequently incomprehensible for outsiders;

7. create (usually at a cost) systems for education and certification, and their methods are frequently subject to copyrights, patents, and trademarks.

The greater the number of these traits characterise the present approach on the market to trainings, the higher the probability that we are dealing with pseudoscience packed in a colourful, shiny box whose contents will not live up to the promises of its marketing.

1. Baddeley, M. (1989). Neurolinguistic programming: The academic verdict so far. Australian Journal of Clinical Hypnotherapy and Hypnosis, 10, 73–81.

2. Bandler, R., & Grinder, J. (1979). Frogs into princes, Moab, UT: Real People Press.

3. Bateson, G. (1979). Mind and nature: A necessary unity (advances in systems theory, complexity, and the human sciences). Cresskill, NJ: Hampton Press.

4. Baumeister, R. F., Bratslavsky, E., Finkenauer, C., & Vohs, K. D. (2001). Bad is stronger than good. Review of General Psychology, 5, 323–370.

5. Beyerstein, B. L. (2001). Fringe psychotherapies: The public at risk. The Scientific Review of Alternative Medicine, 5, 70–79.

6. Brown, N. (2004). What makes a good educator? The relevance of meta programmes. Assessment & Evaluation in Higher Education, 29, 515–533.

7. Cialdini, R. B. (1980). Full-cycle social psychology. Applied Social Psychology Annual, 1, 21–47.

8. Devilly, G. J. (2005). Power therapies and possible threats to the science of psychology and psychiatry. Australian and New Zealand Journal of Psychiatry, 39, 437–445.

9. Dilts, R. (1983). Roots of neurolinguistic programming. Capitola, CA: Meta Publications.

10. Dilts, R. (1998). Modeling with NLP. Capitola, CA: Meta Publications.

11. Dilts, R. (2003). From coach to Awakener. Capitola, CA Meta Publications.

12. Dorn, F. J., Brunson, B. I., Bradfor, I., & Atwater, M. (1983). Assessment of primary representational systems with neurolinguistic programming: Examination of preliminary literature. American Mental Health Counselors Association Journal, 5, 161–168.

13. Einspruch, E. L., & Forman, B. D. (1988). Neurolinguistic Programming in the treatment of phobias. Psychotherapy in Private Practice, 6, 91–100.

14. Grinder, J., & Bandler, R. (1976). The structure of magic II. Palo Alto, CA: Science and Behavior Books.

15. Grinder, J., & Bandler, R. (1981). Transe-formations: Neuro-linguistic Programming^TM and the structure of hypnosis. Moab, UT: Real People Press.

16. Heap, M. (1988). Neurolinguistic programming: An interim verdict. In M. Heap (Ed.), Hypnosis: Current clinical, experimental and forensic practices (pp. 268–280). London, UK: Croom Helm.

17. Heap, M. (2008). The validity of some early claims of neurolinguistic programming. Skeptical Intelligencer, 11, 1–8.

18. Hoag, J. D. (2018). NLP meta programs [Blog post]. Retrieved from http://nlpls.com/articles/metaPrograms.php

19. Horn, L. R. (1996). Presupposition and implicature. In S. Lappin (Ed.), The handbook of contemporary semantic theory (pp. 299–320). Blackwell Handbooks in Linguistics. Oxford: Blackwell.

20. Korzybski, A. (1933). A non-Aristotelian system and its necessity for rigour in mathematics and physics. In: Science and Sanity: An introduction to non-Aristotelian systems and general semantics (pp. 747–761). Lakeville, CT: International Non-aristotelian Library Publishing Co. www.bibsonomy.org/bibtex/1d8845e1a33fdcf1c6f18b1cb2d37c0c1/voj

21. Krugman, M., Kirsch, I., Wickless, C., Milling, L., Golicz, H., & Toth, A. (1985). Neuro-Linguistic Programming treatment for anxiety: Magic or myth? Journal of Consulting and Clinical Psychology, 53, 526–530.

22. Lankton, S. (1980). Practical magic, Cupertino, CA: Meta Publications.

23. Methods of neuro-linguistic programming. (n.d.). In Wikipedia. Retrieved October 20, 2018, from https://en.wikipedia.org/wiki/Methods_of_neuro-linguistic_programming

24. Moore, W. J., Manning, S. A., & Smith, W. I. (1978). Conditioning and instrumental learning. New York, NY: McGraw-Hill Book Company, pp. 52–61.

25. Newbrook, M. (2008). Linguistic aspects of “Neurolinguistic programming”. Skeptical Intelligencer, 11, 27–29.

26. Ng, C., & Benedetto, U. (2016). Evidence hierarchy. In G. Biondi-Zoccai & G. Biondi-Zoccai (Eds.), Umbrella reviews: Evidence synthesis with overviews of reviews and meta-epidemiologic studies (pp. 11–19). Cham, Switzerland: Springer International Publishing.

27. Norcross, J. C., Koocher, G. P., & Garofalo, A. (2006). Discredited psychological treatments and tests: A Delphi Poll. Professional Psychology: Research and Practice Copyright, 37, 515–522.

28. O’Connor, J., & Seymour, J. (1993). Introducing neuro-linguistic programming: Psychological skills for understanding and influencing people. London, UK: Thorsons.

29. Page, S., & Meerabeau, L. (2004). Hierarchies of evidence and hierarchies of education: Reflections on a multiprofessional education initiative. Learning In Health & Social Care, 3(3), 118–128. doi:10.1111/j.1473–6861.2004.00070.x

30. Petrisor, B.A, & Bhandari, M. (2007). The hierarchy of evidence: Levels and grades of recommendation. Indian Journal of Orthopaedic, 41(1), 11–15.

31. Roderique-Davies, G. (2009). Neuro-linguistic programming: Cargo cult psychology? Journal of Applied Research in Higher Education, 1, 57–63.

32. Sharpley, C. F. (1984). Predicate matching in NLP: A review of research on the preferred representational system. Journal of Counseling Psychology, 31, 238–248.

33. Sharpley, C. F. (1987). Research findings on neurolinguistic programming: Nonsupportive data or untestable theory? Journal of Counseling Psychology, 34, 103–107.

34. Sturt, J., Ali, S., Robertson, W., Metcalfe, D., Grove, A., Bourne, C., & Bridle, C. (2012). Neurolinguistic programming: A systematic review of the effects on health outcomes. The British Journal of General Practice, 62(604), e757–e764. doi:10.3399/bjgp12X658287

35. Swets, J. A., & Bjork, R. A. (1990). Enhancing human performance: An evaluation of “New Age” techniques considered by the U.S. army. Psychological Science, 1, 85–86.

36. Vaknin, S. (2010). The Big Book of NLP, Expanded: 350+ techniques, patterns & strategies of neuro linguistic programming. Inner Patch Publishing.

37. Von Bergen, C. W., Soper, B., Rosenthal, L. V., & Wilkinson, L. V. (1997). Selected alternative training techniques in HRD. Human Resource Development Quarterly, 8, 281–294.

38. Witkowski, T. (2010). Thirty-five years of research on neuro-linguistic programming. NLP research data base. State of the art or pseudoscientific decoration? Polish Psychological Bulletin, 41(2), 58–66.

39. Witkowski, T. (2012). A review of research findings on neuro-linguistic programming. The Scientific Review of Mental Health Practice, 9(1), 29–40.

40. Zaharia, C., Reiner, M., & Schütz, P. (2015). Evidence-based neuro linguistic psychotherapy: A meta-analysis. Psychiatria Danubina, 27(4), 355–363.