In 1999, David Dunning and Justin Kruger published a journal article entitled ‘Unskilled and Unaware of It: How Difficulties in Recognizing One’s Own Incompetence Lead to Inflated Self-Assessments’. Their research indicated that people who are unskilled, or lacking academic or professional qualifications in a particular field, have a tendency to estimate their knowledge and skills in that field unrealistically highly.
Citing the observation of Charles Darwin that ‘ignorance more frequently begets confidence than does knowledge’, Dunning and Kruger explained the cognitive process by which people over-estimate their competence in fields concerning which they are unskilled or uninformed. In agreement with the popular saying ‘a little learning is a dangerous thing’, Dunning and Kruger noted ‘in order for the incompetent to overestimate themselves, they must satisfy a minimal threshold of knowledge, theory, or experience that suggests to themselves that they can generate correct answers’.
Accordingly, we ought to refrain from commenting authoritatively on subjects concerning which we are not academically informed or professionally qualified, and should instead seek to understand the subject from the relevant professional literature, instead of from non-professionals and those who are insufficiently qualified.
Additionally, we should be prepared to accept that our non-professional personal views (and the views of others who are similarly unqualified in the field), are of considerably less value than the existing scholarly literature and consensus, and we should be prepared to accept that the consensus is most likely to be correct, even if it contradicts views or sources which we would prefer to believe are more accurate.
The following dot points list indicators of the Dunning-Kruger effect, based on the reasons given by Dunning and Kruger as to why individuals succumb to the effect, and why they ‘fail, through life experience, to learn that they are unskilled’. The more indicators are present in a specific case, the more likely it is that the individual in question is experiencing the effect.
- Skill-boundary transgression: The individual is seeking to operate as an authority or qualified individual, in a field beyond their personal level of academic and professional qualification.
- Self-identified authority: The individual identifies themselves as sufficiently competent to comment authoritatively on the subject. 
- Unrecognized competence: The individual’s self-assessed competence is not recognized by those who are academically and professional competent.
- False peers: The individual believes that the favourable commentary of other unskilled and non-professional individuals, indicates they themselves are sufficiently qualified.
- Scrutiny avoidance: The individual fails to submit their work for professional scrutiny (such as in the relevant scholarly literature), for review by those genuinely qualified.
- Pioneer complex: The individual self-identifies as a pioneer unconvering previously unknown or unrecognized facts; a Copernicus or Galileo.
- Conspiracy claims: The individual explains opposition by qualified professionals as a coordinated attempt to suppress truth, in order to defend the existing scholarly consensus.
- Allocentric  claims of bias: The individual explains the difference between their views and those of qualified professionals, as the result of inherent bias on the part of the professionals; accusations of bias are directed at anyone other than themselves, and they claim objectivity.
 Kruger & Dunning, ‘Unskilled and Unaware of It: How Difficulties in Recognizing One’s Own Incompetence Lead to Inflated Self-Assessments’, Journal of Personality and Social Psychology (77.6.1121-1134), 1999.
 Darwin, ‘The Descent of Man, and Selection in Relation to Sex’ volume 1, p. 4 (1871).
 Commonly misquoted as ‘A little knowledge is a dangerous thing’, this phrase is a line from English poet Alexander Pope’s poem ‘An Essay on Criticism’ (1709).
 Kruger & Dunning, ‘Unskilled and Unaware of It: How Difficulties in Recognizing One’s Own Incompetence Lead to Inflated Self-Assessments’, Journal of Personality and Social Psychology (77.6.1132), 1999.
 Ibid., pp. 1131.
 ‘Incompetent individuals, compared with their more competent peers, will dramatically overestimate their ability and performance relative to objective criteria.’, ibid., p. 1122; the importance of formal academic and professional qualifications is that they constitute objective criteria by which competency can be assessed, so we should place less trust in those lacking such qualifications.
 ‘These findings suggest that unaccomplished individuals do not possess the degree of metacognitive skills necessary for accurate self-assessment that their more accomplished counterparts possess.’, ibid., p. 1122; we cannot rely on those who are not academically and professionally qualified in a particular field, to assess accurately their own authority and competence in that field.
 ‘We propose that those with limited knowledge in a domain suffer a dual burden: Not only do they reach mistaken conclusions and make regrettable errors, but their incompetence robs them of the ability to recognize it.’, p. 1132;. it is far more likely that an unqualified non-professional will be wrong in a given field of specialization, than a qualified professional whose competency has been recognized formally by their equally qualified peers
 ‘Second, the bungled robbery attempt of McArthur Wheeler not withstanding, some tasks and settings preclude people from receiving self-correcting information that would reveal the suboptimal nature of their decisions (Einhorn, 1982).’, ibid., p. 1131; by keeping themselves predominantly in the intellectual company of those who agree with them, individuals experiencing the Dunning-Kruger effect place themselves in a setting which typically prevents their errors being exposed, instead keeping them in a kind of intellectual echo chamber in which their views are reinforced by being repeated back to them with approval by those unqualified to assess them competently.
 ‘One reason is that people seldom receive negative feedback about their skills and abilities from others in everyday life (Blumberg, 1972; Darley & Fazio, 1980; Goffman, 1955; Matlin & Stang, 1978; Tesser & Rosen, 1975)’, ibid., p. 1131; avoidance of scrutiny by professionals enhances this effect, keeping the unqualified away from those who are best able to expose their errors, and preserving their self-delusion that they are correct.
 This is a self-delusional identification since neither Copernicus nor Galileo were ‘gifted amateurs’ opposing a body of professionals (both men were professionals, holding formal teaching positions), and Galileo in particular knew that the subject should be decided by professionals astronomers, placing no value whatsoever on the opinions of the unqualified; writing against the papal edict silencing publications on heliocentrism in the preface of his ‘Dialogue’ (1632), Galileo scorned the unqualified amateur: ‘Complaints were to be heard that advisors who were totally unskilled in astronomical observations ought not to clip the wings of reflective intellects by means of rash prohibitions.’, Galileo, quoted in Næss, ‘Galileo Galilei: When the Earth Stood Still’, p. 131 (2005).
[12 ‘Third, even if people receive negative feedback, they still must come to an accurate understanding of why that failure has occurred. The problem with failure is that it is subject to more attritional ambiguity to success. For success to occur, many things must go right: The person must be skilled, apply effort, and perhaps be a bit lucky. For failure to occur, the lack of any one of these components is sufficient. Because of this, even if people receive feedback that points to a lack of skill, they may attribute it to some other factor (Snyder, Higgins, & Stucky, 1983; Snyder, Shenkel, & Lowry, 1977).’, ibid., p. 1131; when an unqualified non-professional attributes opposition to or dismissal of their theories by qualified professionals as a conspiracy to maintain the intellectual status quo, the Dunning-Kruger effect is very likely responsible: an example is the Science and Public Policy Institute (a non-profit group in the US which opposes the scientific consensus on global warming), ‘People who are not scientists, or even experts on the subjects they write about often write the SPPI reports, and many convey conspiratorial themes. For example, an SPPI publication by Joanne Nova, who describes herself as a “freelance science presenter, writer, & former TV host”, exemplifies not only the ‘Dunning-Kruger’ effect (Dunning et.al. 2003), but also the inactivist movement’s frustration with mainstream climate science and its inflated sense of victimhood.’, Elshof, ‘Can Education Overcome Climate Change Inactivism?’, Journal for Activism in Science and Technology Education (3.1.25), 2011.
 Allocentric means ‘focused on others’, or ‘aimed at others’.