Diagnosing dyslexia in adults: what is going wrong and how can we fix it?

This paper examines how the concept of dyslexia, a problem that was once considered to be both rare and highly salient, has now been broadened to such an extent that many adults with successful educational histories, and without any history of significant reading difficulty, receive a dyslexia diagnosis only after having progressed to higher education, training, or employment. It is argued that the basis of the problem lies largely in conceptual and scientific misunderstandings. While there is a wide consensus that dyslexia represents a severe, complex, and persistent difficulty in learning to decode text, many have placed undue emphasis upon a wide variety of cognitive processes as diagnostic indicators. The primary error stems from conflating the greater likelihood of finding such difficulties in groups of struggling readers with the belief that these can be adjudged to be markers of dyslexia in the case of a given individual. This misconception has been exacerbated by a growing emphasis upon self-reported difficulties and the use of lived experience as primary means of understanding the nature of the condition. The dangers that result for scientific advance and for evidence-led educational policy and practice are highlighted. It is contended that the expansion of the dyslexia construct, and the misuse of assessment data, particularly when employed with adults, has in part been fueled, not by scientific research, but by the misunderstandings, interests, and motivations of those receiving and providing diagnostic services. Illustrative examples from the domains of adult higher education, medical training, and employment tribunals are offered as illustration.