Medical Model of (Dis)Ability


Medical Model of Ability
Medical Model of Disability


Differences among individuals used to account for differences in learning

Principal Metaphors

Discourses on ability and disability draw on a wide range of metaphors, but conceptions trend strongly to notions consistent with Folk Theories. Two old, but still prominent metaphors are ability as capacity (i.e., amount that can be held) and ability as speed,” and others are developed more below. Since the mid-1900s, Brain-as-Computer Discourses, especially Cognitivism and Cognitive Processes, have been especially influential in framing the Medical Model of (Dis)Ability, and so the following cluster of metaphors are currently pervasive in discussions of ability and disability.
  • Knowledge is … information
  • Knowing is … using information
  • Learner is … an information processor (individual)
  • Learning is … inputting (and associated computer-based notions, such as processing, storing, and retrieving)
  • Teaching is … transmission (of information)
The are many metaphors associated with ability (and, by implication, disability), each tied into grander webs of metaphor used to interpret learning. Some of the more prominent examples include:
  • Brightness, Brilliance (Dimness) Metaphor – strongly associated with the Illumination Metaphor, framing intelligence in terms of Brightness (or Dimness) tends to prompt attentions toward accuracy of observation, clarity of expression, and sunniness of disposition
  • Capacity Metaphor (Capacity Model) – having to do with how much a container can hold (and so characterizing the ability at hand as a limited possibility or finite resource). An ability-as-capacity metaphor is strongly associated with the Acquisition Metaphor and tends to prompt attention to matters of extent and measurability – of memory, attention, endurance, and so on.
  • Cleverness Metaphor – tracing to the Proto-Indo-European root gleubh- “to tear apart, cleave,” Cleverness likely came into popular use for the same reason as Sharpness (see below)
  • Enrichment Metaphor – meaning literally “make more wealthy,” a notion that aligns with the Talent Metaphor and the Giftedness Metaphor, and that is typically actualized in educational settings as the provision of more challenging and/or more varied learning activities intended to amplify perceived talents and gifts
  • Exceptionality Metaphor – a more recent construct that’s based on the Normal Distribution (see below), descriptive of performances that are a predefined “distance” from a Norm
  • Genius Metaphor – from the Latin gens “generative power,” Genius presses attentions to abilities to produce new insight and possibility, and is thus frequently aligned with Creativity Discourses
  • Giftedness, Endowment (Handicap) Metaphor – reflecting assumptions of Nativism, the metaphor operating here has to do with having been bestowed something – and, in the case of Handicap, that something is an additional burden
  • Intelligence Metaphor – derived from the Latin intelligentia “power of discerning,” Intelligence likely came into popular use for the same reason as Sharpness (see below)
  • Potential Metaphor – derived from the Latin potens “powerful,” Potential has been taken up in two incompatible ways to refer to ability, one that aligns with Giftedness and Capacity (see above) with a sense of predetermined limits, and the other that aligns more with Strength (see below) and a sense of developable possibility
  • Quickness (Delayed; Slowness; Retardation) Metaphor – intelligence and other abilities are often interpreted in terms of speediness (or slowness) in developing competence, thus fitting well with the Attainment Metaphor
  • Sharpness, Acuity (Dullness) Metaphor – prompts attentions to one’s ability to notice – that is, to the precision and utility of perceptual discernments
  • Smartness Metaphor – derived from the Old English word for “cutting,” Smartness likely came into popular use for the same reason as Sharpness (see above)
  • Strength (Weakness) Metaphor – the separation of “strong students” from “weak students” suggests that ability is understood in terms of force, endurance, and focus – and, in some contexts, to the benefits of practice/exercise (i.e., likening the brain to a muscle)
  • Talent Metaphor – derived from the Latin talentum “weight, sum,” Talent was originally applied to anything measured or measurable – and so, as a metaphor for ability, it prompts notions of clear definition and quantifiability
The assumption of measurability, which is present in most of the above metaphors, is essential to the Medical Model of (Dis)Ability. Specifically, that assumption aligns with the popular conviction that mental abilities are like physical attributes – and so can and should be measured, along with the belief that such measurements must be normally distributed. Underlying constructs and associated discourses include:
  • Continuum Approach – the perspective that differences among individuals are matters of degree rather than type – that is, that traits and behaviors range along continua, from highly dysfunctional/abnormal to highly functional
  • Normal Distribution (Bell Curve) – a mathematical model based on two pieces of information: the mean (i.e., the arithmetic average or the Norm, at the center) and the standard deviation (i.e., an indication of how data are spread out; in the image below, each shaded region has a width of one standard deviation). For normally distributed phenomena, most data points cluster around the mean, with more than 68% of data points falling within one standard deviation (i.e., in the dark grey regions on the image). As one moves further from the mean, the likelihood of a result becomes very small. Types of Normal Distributions include:
    • Standardized Distribution (Standard Normal Distribution; Unit Normal Distribution) – a Normal Distribution for which the mean has been set to 0 and the standard deviation adjusted to 1
  • Norm – mathematically, an average or mean – and so, in the context of the Medical Model of (Dis)Ability, the standard, typical, or expected (i.e., at the center of the Normal Distribution)
  • Normal (Normality) – conforming to a Norm – and so, in the context of the Medical Model of (Dis)Ability, typically defined as being within one standard deviation of the Norm (i.e., the dark grey region of the above image)
  • Abnormal (Abnormality) – departing from a Norm – which, in the context of the Medical Model of (Dis)Ability, is often defined as more than two standard deviations from the mean (i.e., the lightest shaded regions in the above image)
  • Normative (Normativity) – the imposition of a standard, based on an assumed and/or dominant conception of Normal – typically, in ignorance of cultural, racial, social, gender, or other considerations of difference
  • Normalism (Normism) – Used by some in philosophy as a synonym to Realism, in education, Normalism is an ambiguous term that, depending on context, can refer to the state of being Normal, the process of returning to Normality, or the imposition of some Normative
  • Norming – the processes of (1) constructing (i.e., isolating, defining, and devising a test to measure) a psychological trait or a performance category and (2) assessing and ranking individuals based on such constructs. Among the many instances of Norming that could be mentioned, the following are especially prominent in the current educational literature:
    • Race Norming – now illegal in many nations, the use of cut-off scores on tests of Ability and/or Aptitude (see Medical Model of (Dis)Ability) for applicants of different racial groups
    • Banding (Score Bands) – an approach to using scores on tests of Ability and/or Aptitude (see Medical Model of (Dis)Ability) to screen applicants by creating ranges of scores (“bands”) rather than ranking each person individually. Everyone landing in the same band is considered equally qualified.
  • Reliability Theory – any perspective on why scores on tasks or tests are consistent across contexts. Prominent Reliability Theories include:
    • Classical Test Theory – the perspective founded on the convictions that (1) one’s traits persist throught time and (2) psychological tests afford reliable indications of whatever they’re purported to measure, provided one parses the “true score” (i.e., the part of the measurement that accurately reflect the attribute) from errors introduced by flawed design, disruptive circumstances, or random error.
    • Generalizability Theory – a formal system of principles and processes for establishing and asserting the accuracy of a psychological tests – that is, for making claims that can be applied across different population groups and subgroups. (Contrast: Item Response Theory, see below.)
    • Item Response Theory (Frederick M. Lord, 1950s) – a perspective that grapples with the possibility that an item on a psychological test might be randomly answered correctly. Such answers might be indicators of a trait that is not being measured deliberately. (Contrast: Generalizability Response Theory, see above.)
  • Standard Error of Measurement – a mathematical construct, the value of which is based on the variations in individuals’ scores across multiple administrations of the same test. That is, the Standard Error of Measurement is an indicator of how confident one can be in the accuracy of a test result.
  • Supernormal – a category of that captures those with a measured attribute that is “far” above the range of Normal. The meaning of “far” very across usages, but a typical value is at least 3 standard deviations (i.e., in the white region on the right under the curve, above).




The Medical Model of (Dis)Ability is, obviously, a medical model or organic approach:
  • Medical Model – an umbrella term that applies to perspectives that assume that mental and psychological problems are analogous to physical and physiological problems – thus prompting attentions to, for example, “symptoms,” “diagnoses,” “treatments,” and “cures”
  • Organicism (Organic Approach) – the view that all mental disabilities and disorders are physically rooted – and, thus, appropriately interpreted and addressed through a medicalized model
To emphasize, a Mental Model embraces a metaphor or analogy. It does not assert a that mental issues are literally like physical ones, which would entail a different paradigm:
  • Physiological Paradigm – the belief that mental disabilities and disorders are rooted into neurological structure – and, so, can be treated using the same techniques for other bodily malfunctions (e.g., drugs, surgery)
The assumed analogy (that mental issues are like physical issues) is evident in foundational constructs of the Medical Model of (Dis)Ability:
  • Mental Disease – an synonym for Mental Disorder (see below), now obsolete and considered offensive
  • Mental Disorder (Mental Illness; Psychiatric Disorder; Psychiatric Illness; Psychological Disorder) – any condition that manifests as learning or cognitive impairments, emotional disturbances, and/or aberrant behaviors.
Within education, the Medical Model of (Dis)Ability tends overwhelmingly to be framed in terms of diagnosis and remediation – that is, academic ability and disability are usually treated as analogous to physical prowess and physical weakness. Traits and performances, whether perceived as outstanding or problematic, are thus attributed solely to the individual. Accordingly, interventions to supplement excellence and to remediate inadequacy are most often focused on the person. (Contrast: Social Model of (Dis)Ability and Neurodiversity.) Relevant constructs include:
  • Diagnosis and Remediation (Remedial Learning) – metaphors borrowed from medicine and applied uncritically to contexts of learning – not to understand or take advantage of differences among learners, but in efforts to be rid of such differences
  • Diagnostic Tests (Diagnostic Assessments) – tests that are designed to identify and measure learning disabilities and disorders for the purpose of prescribing some manner of remediation to address a formal diagnosis. [Compare: Ability Tests, below; Achievement Tests, under Assessment and Evaluation.] Diagnostic Tests are based on the questionable assumption/analogy that difficulties with learning are like medical illnesses. Most are focused on reading/literacy; behavior and mathematics are well represented as well. For the most part, Diagnostic Tests are indexed to specific curricula and jurisdictions – which helps to explain why there are many, many options available.
  • Mental Measurement (Mental Testing) – the interpretation of psychological processes in terms of scales and/or ratios
  • Psychometrics (Psychometric Psychology; Psychometry) the area of Psychology that deals with quantification and measurement of of learning, cognition, behavior, achievement, and so on. Methodology is a principal focus of the area, addressing such matters as development and validity of tests, questionnaires, observation protocols, and so on. Subdiscourses relevant to education include:
    • Psychoeducational Diagnostician – a specialist with qualifications in Psychometrics who focuses on diagnosing and assessing learning problems, especially disabilities
The assumptions underlying and aggregated results of such attitudes and tools have been codified:
  • Diagnostic and Statistical Manual of Mental Disorders (DSM) (American Psychological Association, currently in its 5th edition, 2013) – an intended-to-be comprehensive manual covering the classification, diagnosis, and treatment of mental disorders, as interpreted through a medical model
  • International Classification of Diseases (World Health Organization, currently in its 11th edition, 2022) – the global standard for diagnosis of all heath conditions. The chapter devoted to Mental Disorders was developed alongside the Diagnostic and Statistical Manual of Mental Disorders (see below).
Beyond education, the Medical Model of (Dis)Ability is assumed and orients the following domains:
  • Abnormal Psychology – the branch of Psychology concerned with the study and treatment of Mental Disorder, especially as manifest in maladaptive behavior
  • Psychopathology – the study of Mental Disorder. Psychopathology is especially informed and oriented informed by research in biochemistry, pharmacology, neurology, and endocrinology.
Notably, the Medical Model of (Dis)Ability and Motivation Theories complement one another. The former address what learners can/can’t do, and the latter deal with what learners will/won’t do. A comprehensive analysis of the Medical Model of (Dis)Ability is beyond our interests and purpose, and so we suffice with brief summaries of several contemporary theories, categorized as “Models and Types of Intelligence,” “Measures of Ability,” “Measures of Aptitude,” “Types of Disabilities,” “Types of Learning and Developmental Disorders,” and “Sorts of Intervention.”
Sampling of Models and Types of Intelligence (listed in chronological order, by decade)
  • Two-Factor Theory [of Intelligence] (Charles Spearman, 1900s) – a perspective that intelligence consists of two abilities which, when measured, translate into two factors:
    • General Ability (General Mental Ability) – an ability assumed to be involved in every type of cognitive tasks and so pervades all intelligence tests. Its measured value is represented as:
      • g (g Factor; General Intelligence Factor; Spearman’s G) – postulated as the core human intelligence; derived from factor analyses of correlations among different IQ tests
    • Specific Abilities (Special Aptitudes) –abilities that are fitted to specific types of cognitive tasks and that do not correlate with one another. The measured value of Specific Abilities is represented as:
      •  s (s Factor; Special Factor; Specific Factor; Spearman’s S) – postulated as a task-focused aspect of human intelligence; derived from a focused tests (on, e.g., mathematical ability)
  • Intelligence Quotient (IQ) (William Stern, 1910s): a numerical rating of intelligence as measured by psychological tests, in which a score of 100 is understood as the population mean. IQ scores are generally understood to comprise two broad elements:
    • Performance IQ – a measure of the intelligence associated with tasks that do not require use of language. Tests typically focus on assessments of perception and processing skills.
    • Verbal IQ – a measure of intelligence associated with use of abstract symbols, verbal memory, and linguistic fluency. Test typically focus on comprehension (e.g., of words, sentences, and arithmetic statements) and short-term memory.
aaaaModes of generating of IQ scores include:
    • Ratio IQ – the ratio of “mental age” to “chronological age,” generated by dividing the former by the latter and multiplying by 100. This mode is now considered outdated.
    • Deviation IQ – an indication of how far one differs from the mean on an IQ test, where the population mean is set at 100 and the standard deviation is set at approximately 15 points (and so, for example, a score of 83 would be just past one standard deviation below the mean – meaning, in terms of the image of the Normal Distribution nearer the top of this entry, the person would land in the mid-grey region on the left side of the distribution)
  • General Intelligence (Raymond Cattell, 1960s): a combination of Fluid Intelligence and Crystallized Intelligence:
    • Fluid Intelligence (Fluid Abilities) (Raymond Cattell, 1960s) – one’s capacity to solve new reasoning problems, making minimal demands on prior learnings. Associated abilities include memory span and mental speed, which peak when young and decline with age.
    • Crystalized Intelligence (Raymond Cattell, 1960s) – one’s ability to apply prior learnings to solve abstract problems – in particular, by applying logic or other formal reasoning skills. Associated abilities include language, social competencies, and cultural awarenesses.
  • Radex Model of Intelligence (Louis Guttman, 1960s) – an image-based interpretation of intelligence making use of a polar coordinate system, with General Intelligence (see above) plotted at the center and other abilities plotted along radial lines
  • Emotional Intelligence (Emotional Intelligence Quotient, Emotional Leadership, Emotional Quotient; Michael Beldoch, 1960s): ability to recognize one’s own and others’ emotions, to use those recognitions effectively, and to manage one’s own emotions in enabling ways
  • PASS Theory of Intelligence (A.R. Luria, 1960s): model of cognition based on four brain-based processes (planning, attention, simultaneous processing, successive processing)
  • Social Intelligence (Joy Paul Guildford, Nicholas Humphrey; Ross Honeywell, 1960s): of self- and social-awareness along couple with ability to effect social change; argued by some as the intelligence that defines humans (vs. IQ). Associated constructs include:
    • Social Quotient (Social Intelligence Quotient) (Sara Sparrow, David Balla, 1980s) – an index of social maturity, expressed as the ratio between social age and chronological age.
  • Biological Intelligence (Ward C. Halstead, 1950s) – the aspect of mental ability that (it is assumed) is biologically rooted. The notion was proposed to highlight the role of forebrain functioning in intelligence.
  • Structure of Intellect Theory (Joy Paul Guilford, 1960s): a model of up to 180 intellectual abilities, organized along the three dimensions of operations (cognition, memory recording, retention, divergent production, convergent production, evaluation), content (figural, symbolic, semantic, behavioral) and product (units, classes, relations, systems, transformation, implications)
  • Dual-Process Theory of Intelligence (Jonathan Evans, 1970s): a two-factor model (explicit, goal-directed, controlled, conscious processes; implicit, spontaneous, automatic, unconscious processes)
  • Level I–Level II Theory (Arthur Jenson, 1970s) – a division of cognitive abilities into two hierarchical categories: Level I, Associative Processing (e.g., rote learning and short-term recall) and Level II, Conceptual Processing (e.g., categorizing, abstraction, reasoning)
  • Three-Ring Conception of Giftedness (J.S. Renzulli, 1970s) – the suggestion that giftedness arises in the intersection of intelligence, creativity, and task commitment
  • Spatial Ability / Spatial Reasoning (Visuo-Spatial Ability; diverse authorship, 1980s): the ability to extend understanding and memories of spatial relations (among objects or space) and orientations (of the actions) into useful strategies and tools for reasoning
  • Cattell–Horn–Carroll Theory (Raymond B. Cattell, John L. Horn, John B. Carroll, 1990s): a model of intelligence divided into 10 broad abilities (fluid intelligence, crystalized intelligence, quantitative reasoning, reading & writing ability, short-term memory, long-term storage & retrieval, visual processing, auditory processing, processing speed, decision/reaction time/speed) and 70 narrow abilities
  • Three-Stratum Theory (John Carroll, 1990s): a mash-up of g Factor and Generalized Intelligence (see above), in which intelligence is described as a three-layer hierarchy. Stratum III is the g Factor, which is seen to emerge from the eight broad abilities of Stratum II (fluid intelligence, crystallized intelligence, general memory and learning, broad visual perception, broad auditory perception, broad retrieval ability, broad cognitive speediness, processing speed), which in turn emerge from many and diverse specific factors that constitute Stratum I.
  • g-VPR Model  (Wendy Johnson, Thomas J. Bouchard Jr., 2000s): a model of intelligence that describes it as a four-layer hierarchy. The fourth stratum is the g Factor, which is seen to emerge from the verbal, perceptual, and rotation factors that constitute third stratum, which in turn emerges from many and diverse narrow abilities that constitute second stratum, which arises from the first stratum that comprises primary traits.
Sampling of Measures of Ability (listed in chronological order of original development, by decade)
In formal education, “achievement,” “intelligence,” and “ability” are commonly distinguished – and their defined differences are especially obvious in the sorts of tests and tools created to measure them. Achievement is principally about student progress in a program of studies (see Assessment and Evaluation for an overview of associated emphases and tools); whereas “intelligence” is typically about assumed-to-be-innate intelligence (see the previous section). Most often, ability is understood to involve both achievement and intelligence:
  • Ability Test (School Ability Test) – a formal assessment of one’s achievements and intelligence, usually with the intention of informing subsequent aspects of the learner's formal education
The following is a sampling of Ability Tests (listed chronologically):
  • Primary Abilities Test (Primary Mental Abilities Test) (Louis Thurstone, 1930s) – a test that generated scores on seven “primary (mental) abilities: Memory, Numerical Ability, Perceptual Speed, Reasoning, Spatial Intelligence, Verbal Ability, Word Fluency
  • Raven’s Progressive Matrices (Raven’s Matrices; RPM) (John C. Raven, 1930s): a non-verbal, 60-item, multiple-choice, group-administered test requiring takers to look for and apply one or more relationships among spatially organized objects. For ages 5 through elderly.
  • Cattell Culture Fair Intelligence Test (CFIT) (Raymond Cattell; 1940s): an effort to construct an intelligence test that is free of sociocultural and environmental influences – a goal that sociologists, anthropologists, and others have since argued to be all but impossible … and not especially desirable. It comprises three scales with non-verbal visual puzzles.
  • Wechsler Intelligence Scales for Children, Fifth Edition (WISC-V) (David Wechsler; originally developed in 1940s; most recently revised in 2010s): an hour-long test that produces both a general intelligence score and scores in five cognitive domains (Verbal Comprehension Index, Visual Spatial Index, Fluid Reasoning Index, Working Memory Index, Processing Speed Index). Supplementary subtests can be used to assess Learning Disabilities. For ages 6 to 16.
  • Stanford–Binet Intelligence Scale, Fifth Edition (SB5) (originally developed by Alfred Binet in 1905; further developed by Lewis Terman in the 1950s; most recently revised in 2000s): an individually administered test comprising ten subtests, used to diagnose learning, developmental, and intellectual problems in young children across five factors (Knowledge, Quantitative Reasoning, Visual-Spatial Processing, Working Memory, Fluid Reasoning). For ages as young as 2.
  • Wechsler Adult Intelligence Scale, Fourth Edition (WAIS-IV) (David Wechsler; originally developed in 1950s; most recently revised in 2000s): a battery comprising ten core subtests and five supplemental subtests that generate two broad scores on general intellectual ability (Full Scale IQ, General Ability Index) and four index scores (Verbal Comprehension Index, Perceptual Reasoning Index, Working Memory Index, Processing Speed Index). For ages 16 to 90.
  • Wechsler Preschool and Primary Scale of Intelligence, Fourth Edition (WPPSI-IV) (David Wechsler; originally developed in 1960s; most recently revised in 2010s): a 30–60-minute test comprising 14 subtests that can be used to assess general intellectual functioning, identify giftedness, and identify learning difficulties. For ages 2.5 to 7.5, with three indexes for younger children (Verbal Comprehension Index, Visual Spatial Index, Working Memory Index) and two more for older children (Fluid Reasoning Index, Processing Speed Index).
  • Woodcock–Johnson Tests of Cognitive Abilities, Fourth Edition (WJ-IV) (Richard Woodcock, Mary E. Bonner Johnson; originally developed in 1970s, most recently revised in 2010s): comprising a standard battery of 10 tests, an extended battery of 10 more, and a diagnostic supplement with 11 more, the WJ-IV assesses nine broad-stratum abilities (Auditory Processing, Comprehension–Knowledge, Fluid Reasoning, Long-Term Memory, Processing Speed, Quantitative Knowledge, Reading–Writing, Short-Term Memory, Visual-Spatial Thinking). It is normed for ages 2 through the 90s.
  • Developmental NEuroPSYchological Assessment, Second Edition (NEPSY-II) (Marit Korkman, Ursula Kirk, Sally Kemp; originally developed in Finnish in 1980s; most recently revised in 2000s): used to assess abilities related to cognitive disorders that are usually diagnosed in childhood. It comprises 25 subtests across six domains (Attention and Executive Functions, Language and Communication, Sensorimotor Functions, Visuospatial Functions, Learning and Memory, Social Perception). For ages 3 to 16.
  • Kaufman Assessment Battery for Children, Second Edition (KABC-II) (Alan S. Kaufman, Nadeen L. Kaufman; originally developed in 1980s; most recently revised in 2000s): an individually administered test comprising 18 subtests, yielding two general intelligence composite scores (Mental Processing Index, Fluid-Crystallised Index). For ages 3 to 18.
  • Luria-Nebraska Neuropsychological Battery (LNNB) (Charles Golden; 1980s): a 2–3-hour, individually administered test comprising 14 scales (motor, rhythm, tactile, visual, receptive speech, expressive speech, writing, reading, arithmetic, memory, intellectual processes, pathognomonic, left hemisphere, right hemisphere), used to assess neurological issues. For ages 15 and up.
  • Vineland Adaptive Behavior Scales (Sara Sparrow, David Balla,) – a tool to assess four domains of functioning: communication, everyday life, socialization, and motor skills. It can be used for ages infancy to 90 years, and it provides both evaluative (i.e., ranking and diagnostic) and treatment (e.g., educational or rehabilitative) information.
  • Das–Naglieri Cognitive Assessment System (Cognitive Assessment System; CAS) (J.P. Das, Jack Naglieri; 1990s): an individually administered test based on the PASS Theory of Intelligence, aimed as assessing four brain-based processes (Planning, Attention, Simultaneous processing, Successive processing). For ages 5 to 17.
  • Differential Ability Scales (DAS): an individually administered, nationally normed (USA) (Colin D. Elliot; 1990s): test comprising 20 subtests, aimed at measuring verbal and visual working memory, immediate and delayed recall, visual recognition and matching, processing and naming speed, phonological processing, and basic number understanding. For ages 2.5 to 17.
  • Behavior Rating Inventory of Executive Function, Second Edition (BRIEF2) (Gerard A. Gioia, Peter K. Isquith, Steven C. Guy, Lauren Kenworthy; originally developed in the 2000s, revised in the 2010s): a 10-minute, 86-item, individually administered questionnaire assesses impairment of executive function. For ages 5 to 18.
  • Reynolds Intellectual Assessment Scales (RIAS) (Randy Reynolds, Cecil Kamphaus; 2000s): an individually administered test comprising four subtests measuring verbal intelligence and non-verbal intelligence, will a supplementary measure of memory. Normed for ages 3 to 94.
Sampling of Measures of Aptitude (listed in chronological order of original development, by decade)
  • Aptitude is an assumed-to-be-innate ability or disposition in relation to a specific discipline or type of task, work, or career – which, in a Medical Model of (Dis)Ability frame, is predictably associated with:
  • Aptitude Test – a standardized and normed assessments that is intended to quantify one’s abilities, dispositions, and/or potentials for engaging in different tasks and pursuing various careers, especially those that require post-secondary education. In contrast to Achievement Tests (see Assessment and Evaluation), which are intended to gauge what has already been learned, Aptitude Tests are seen to gauge what one might be capable of learning or inclined to learn.
  • Professional Aptitude Test – any test intended to identify and/or channel candidates for training in a profession, such as medicine, law, teaching, nursing, or engineering
Specific Aptitude Tests include:
  • Ohio State Psychological Examination (H.A. Toops, 1910s) – an Aptitude Test for high school students that focuses on verbal competence in relation to possible areas of educational or career specialization
  • American Council on Education Psychological Examination (L.L. Thurston, T.G. Thurston, 1920s) – an Aptitude Test that generates two scores: Linguistic (based on verbal analogies) and Quantitation (focused on arithmetic reasoning and patterns)
  • Kulmann–Anderson Measure of Academic Potential (Frederick Kuhlmann, Rose Anderson, 1920s) ­– an Aptitude Test intended to assess general learning ability in children across grade levels. Currently in its 7th edition, and comprising both verbal and nonverbal subtests that cover a broad range of cognitive skills, it is asserted to be effective at identifying a variety of proficiencies and deficits.
  • Scholastic Aptitude Test (Carl Brighmam, 1920s) – an Aptitude Test focused on “abstract intelligence” that is intended to sort “college material” from among high school students. It generates scores on Verbal (reading, writing, vocabulary) and Mathematics (geometry, arithmetic, algebra)
  • Differential Aptitude Tests (G.K. Bennett, H.G. Seashore, A.G. Wesman, 1940s) – a set of tests to identify strengths and weaknesses across a range of thinking, perceptual, and linguistic skills, used to predict success in school and the workplace
  • College Qualifications Test (E.K. Bennett, 1950s) – an Aptitude Test that is intended not just to effectively sort college applicants, but to predict of their academic success. It yields scores in the usual verbal and numerical realms, as well as in prior learning in the social, physical, and biological sciences.
  • Cooperative School and College Ability Test (Educational Testing Service, 1950s) – an Aptitude Test spanning 4th grade to 2nd year post-secondary that is intended to measure one’s capacity for further schooling. It generates Verbal (vocabulary and reading) and Quantitative (arithmetic) scores.
  • Academic Promise Test (George Bennett, 1960s) – an Aptitude Test for high school students, founded on an assumption of grouping or streaming by ability level. It has four subtests: Verbal (vocabulary), Numerical (number skills), Abstract Reasoning (logic), Language Usage (grammar, usage, spelling)
  • Multidimensional Aptitude Battery II (MAB II) (Douglas N. Jackson; 2010s): a group-administered test comprising 10 subtests to assess verbal ability, performance capacity, and full-scale IQ. Intended for professional and employment setting, it is for ages 16 and up.
Sampling of Types of Disabilities
  • Intellectual Disability (General Learning Disability; Cognitive Impairment; diverse authorship, first records date back more than 2500 years): neurodevelopmental disorder associated with low IQ (<70) and inability to cope with multiple everyday living requirements. The term Intellectual Disability has been in popular usage for some decades now, having replaced prior phrases that make use of now-offensive metaphors of Retardation and Handicap (see the Principal Metaphors section, above, in this entry):
    • Mentally Retarded (Mental RetardationMentally Handicapped) – (now offensive) having an Intellectual Disability
      • Educable Mentally Retarded (Educable Mentally Handicapped; EMH; EMR) – (now offensive) a category of Intellectual Disability typically defined in terms of IQs between 50 and 75 and associated with an achievement expectation in the upper-elementary-school range
      • Trainable Mentally Retarded (Trainable Mentally Handicapped; TMH; TMR) – (now offensive) a category of Intellectual Disability typically defined in terms of IQs under 50 and associated with institutionalized care and limited workshop-based expectations
      • Profound Mental Retardation – having an IQ below 20, associated with lifelong supervision, usually in specialized care situations
      • Unspecified Intellectual Disability (formerly: Mental Retardation, Severity Unspecified; Unspecified Mental Retardation) – a diagnosis used when the assessed individual is too impaired or difficult to be evaluated according to a standardized test
    • Borderline Intelligence (Borderline Intellectual Functioning) – having an Intelligence Quotient that lands near the score used to define an Intellectual Disability, typically identified as 70–75 or as 66–79, depending on the context
    • Marginal Intelligence – having an Intelligence Quotient that lands in the range of 70 to 100 – that is, between an Intellectual Disability and “average”
  • Learning Disability (Specific Learning Disability) (diverse authorship, 1880s): official clinical diagnosis of problems, usually assumed to be associated with a Perceptual Deficit (see below) and/or rooted in atypical brain organization or function. Some LDs are:
    • Dyslexia – difficulty with symbolic forms, especially reading
    • Dysgraphia – difficulty with fine-motor skills, especially affecting writing
    • Dyscalculia – difficulty with arithmetic
    • Dyspraxia – difficulty with purposive actions
    • Dysnomia – difficulty finding and expressing words.
  • Perceptual Deficit (Perceptual Defect) – an impairment associated with sensory experience, associated with one or more of: alerting oneself to notice, orienting one’s focus, maintaining one’s attention, distilling relevant details, analyzing perceived information, or integrating with prior experiences
Sampling of Types of Learning and Developmental Disorders (listed in chronological order, by decade)
Disorders are typically classified according to their bases:
  • Functional Disorder – any Disorder with no clearly identifiable physiological basis
  • Organic Disorder (Organic Disease) – any Disorder with a clearly identifiable physical basis
  • Psychogenic Disorder – any Disorder with no clearly identifiable physiological basis and that is assumed to be due to psychological factors
That said, opinions can vary massively as to whether a particular disorder is Organic or Psychogenic, and in most cases there is consensus that both psychological and physiological factors are at play. Consequently, unless the basis of a specific disorder is known with certainty, it is usually described as a Functional Disorder. Commonly diagnosed disorders include:
  • Learning Disorder (Learning Difficulty; diverse authorship; mid-1800s): inadequate (i.e., below norms) development of specific language or academic skills, but not severe enough to warrant disability diagnosis
  • Movement Disorder (Motor Disorder) (diverse authorship; mid-1800s)– an umbrella term that is applied to any compromise of physical ability that is associated with neurological damage
  • Developmental Disorder (Developmental Disability; diverse authorship; late 1800s) – a chronic condition that impairs mental and/or physical function in ways that significantly limit one or more capacities necessary for major life activities
  • Anxiety Disorders (diverse authorship, 1890s): an array of mental conditions that manifest as debilitating anxieties and fears. Anxiety Disorders that are commonly encountered in educational settings include:
    • Generalized Anxiety Disorder (GAD) – persistent and intense worry and tension, often with no apparent cause or trigger
    • Obsessive-Compulsive Disorder (OCD) (C. Westphal, 1890s) – persistent undesired thoughts (obsessions) and/or repetitive behaviors (compulsions), the latter of which are often undertaken in the hope of ending the former
    • Post-Traumatic Stress Disorder (PTSD) – recurrences of distress subsequent to a traumatic event in which serious harm was endured or threatened
    • School Refusal (School Avoidance) – an Anxiety Disorder affecting approximately 2% of children that manifests as a resistance to attending school. School Refusal is often associated with other Anxiety Disorders and/or Learning Disabilities.
    • Separation Anxiety Disorder (SAD) – persistent worry about being apart from a parent or others with a tight emotional bond that might be associated with or result in a range of pathologies, including clinging to the family members, weeping, headaches, vomiting, School Refusal, poor performance, and problematic social relations.
    • Social Anxiety Disorder (Social Phobia) – extreme and perhaps-debilitating self-consciousness – in some instances specific to one sort of situation and in others generalized to almost any social situation
  • Autism Spectrum Disorder (Autism Spectrum Condition; E. Bleuler, 1910s): a range of neurodevelopmental disorders, manifesting as problems with social engagement and/or repetitive patterns of interest or activity
  • Auditory Processing Disorder (S.J. Kopetzsky, 1940s): difficulties distinguishing, locating, isolating, and interpreting sounds
  • Sensory Processing Disorder (Sensory Integration Dysfunction; A.J. Ayres, 1940s): inadequate coordination of senses, resulting in difficulties in functioning in specific contexts
  • Antisocial Personality Disorder (Dissocial Personality Disorder; Anti-Social Behavior Disorder; DSM, 1950s): general and persistent ignorance of social norms and morals, along with others’ feelings and rights
  • Intermittent Explosive Disorder (DSM, 1950s): intermittent and unpremeditated explosive outbursts that are disproportionate to the situation
  • Language Processing Disorder (diverse authorship, 1950s): difficulties in parsing and interpreting words, sentences and stories
  • Attention-Deficit Disorder (Attention-Deficit Hyperactivity Disorder) (diverse authorship, 1960s): neurodevelopmental issue manifesting as excessive activity, poor self-control, and difficulties with attention
  • Conduct Disorder (diverse authorship, 1960s): violation of age-appropriate norms through persistent and repetitive infringements on others’ rights
  • Emotional and Behavior Disorders (Behavior and Emotional Disorders) (1970s) – an education-based classification that enables schools and other institutions to access services and programs to relevant supports. Operationally, the category is often ill-defined term and used in different, partially overlapping ways, ranging from any pathology or abnormal behavior (and so roughly synonymous to a mental, psychological, or psychiatric condition) to a category of problematic behaviors among pre-adults, ranging from the benignly disruptive (e.g., toe tapping; nail biting) to the outright destructive (e.g., criminal acts, sexual aggressions)
  • Nonverbal Learning Disorder (Helmer Myklebust; 1970s)– limited critical thinking skills and difficulties with nonverbal information
  • Oppositional Defiant Disorder (DSM-3, 1980s): pattern of irritable, argumentative, and/or vindictive behavior in children and adolescents
  • Stereotypic Movement Disorder (DSM-5, 2010s): motor condition involving repetitive and disruptive physical actions
Less clinical, but much more common “diagnoses” associated with entrenched practices of measurement and prediction  include:
  • Overachievement (Achievement Above Predicted Expectations) – success in endeavors that exceed levels predicted by aptitude and/or intelligence tests
  • Underachievement – performance that is consistently below either demonstrated capacities or predictions based on aptitude and/or intelligence tests
Sampling of Sorts of Response/Intervention
  • Ability Grouping – separating learners according to ability and/or performance – typically undertaken on the classroom level and over a relatively short term (of less than a school year) (Contrast with Tracking, above.)
  • Educational Therapy – any intervention that is explicitly designed to address disabilities or disorders that interfere with formal learning
  • Mixed Ability (Differently Abled) – proposed in response to the negative connotations of such labels as “abnormal,” “disabled,” “handicapped,” and “special,” Mixed Ability (and Differently Abled) is sometimes used to describe a person whose physical, emotional, and/or learning abilities fall outside what are considered Normal (see above).
  • Mixed Ability Grouping – the opposite of Tracking (above) and Ability Grouping (above), Mixed Ability Grouping involves teaching individuals with diverse abilities together (Contrast with Diversity Education and Inclusive Education, included as subdiscourses of Activist Discourses.)
  • Pull-Out Program – an intervention approach in which students participate in regular classrooms through most of their time at school, but go to separate classrooms for specialized attention for part of the school day
  • Special Education – formal schooling structures intended to accommodate the particular needs of students with diagnosed learning issues. Most often Special Education involves some manner of segregation. Constructs associated with Special Education include:
    • Special Child – one with Special Needs (see below)
    • Special Needs – mental, physical, and/or emotional issues that disrupt one’s learning. Most Special Needs involve an Intellectual Disability, a Learning Disability, a Learning Disorder, or a Development Disorder, but the construct is sometimes used to capture financial and other situational impediments.
  • Tracking (Streaming; Phasing) – separating learners according to ability and/or performance – typically undertaken on the school level and maintained over years. (Contrast with Ability Grouping, below.)


While it might appear that the above entries present a great deal of conceptual diversity, with regard to implicit assumptions on and metaphors of learning, they are surprisingly similar. – as we have attempted to demonstrate with the list of metaphors near the start of this entry. For the most part, the Medical Model of (Dis)Ability is closely aligned with Correspondence Discourses. For example, a majority assume such dualisms as inside/outside, mental/physical, self/other, and individual/collective. As well, most explicit references to learning invoke Folk Theories (e.g., the Acquisition Metaphor, the Attainment Metaphor, the Illumination Metaphor) or Brain-as-Computer Discourses. Given the strong tendencies toward the sorts of metaphors identified above, it should perhaps not be surprising that the Medical Model of (Dis)Ability is usually associated with strategies to measure and rank. (That is, the above metaphors are readily interpreted in terms of physics, and thus lend themselves to acts of quantification and comparison.) By contrast, conceptions of (dis)ability associated with Coherence Discourses tend to be framed more in terms of growth, expansive possibility, and fitness as they reject the dualisms that infuse the above models. By way of illustration, a Neurodiversity critique of disability and disorder frames has risen to prominence over the past few decades. It rejects the “deficit model” of the learner assumed across most constructs associated with the Medical Model of (Dis)Ability, and it argues that perceived (dis)abilities are indicative of a pool of diversity that is necessary for the survival of the species. That perspective is bolstered by observations that definitions and classifications of (dis)ability vary dramatically across cultures. Some psychologists have responded by tweaking definitions of (dis)ability to include consideration of situation. However, so far, few of those revisions interrogate foundational metaphors and assumed dualisms. Additionally, the simple fact that the multi-billion-dollar industry of intelligence testing is regularly compelled to recalibrate its measures is often cited as an indication of flawed and constrained thinking. Consider, e.g.,
  • Flynn Effect (James R. Flynn, Richard Herrnstein, Charles Murray; 2000s): the multi-decade, transcultural phenomenon of steady and substantial increases in scores on intelligence tests through the 20th century (of about 3 points per decade on a normed 100-point scale)

Authors and/or Prominent Influences


Status as a Theory of Learning

For the most part, the Medical Model of (Dis)Ability is deployed as a cluster of perspectives of learning.

Status as a Theory of Teaching

In general, the Medical Model of (Dis)Ability is not explicit identified as a discourse on teaching, but most of its associated discourses and constructs are routinely invoked to inform or justify pedagogical approaches and curriculum emphases.

Status as a Scientific Theory

Despite the fact that massive research and marketing industries have arisen around the Medical Model of (Dis)Ability, the general failure to interrogate foundational assumptions means that the model itself and few of its associated discourses meet our criteria for scientific theories.


  • Ability Grouping
  • Ability Test (School Ability Test)
  • Abnormal (Abnormality)
  • Abnormal Psychology
  • Academic Promise Test
  • American Council on Education Psychological Examination
  • Antisocial Personality Disorder (Dissocial Personality Disorder; Anti-Social Behavior Disorder)
  • Anxiety Disorder
  • Aptitude
  • Aptitude Test
  • Attention-Deficit Disorder (Attention-Deficit Hyperactivity Disorder)
  • Auditory Processing Disorder
  • Autism Spectrum Disorder
  • Banding (Score Bands)
  • Behavior Rating Inventory of Executive Function, Second Edition (BRIEF2)
  • Biological Intelligence
  • Borderline Intelligence (Borderline Intellectual Functioning)
  • Brightness, Brilliance (Dimness) Metaphor
  • Capacity Metaphor (Capacity Model)
  • Cattell Culture Fair Intelligence Test (CFIT)
  • Cattell–Horn–Carroll Theory
  • Classical Test Theory
  • Cleverness Metaphor
  • College Qualifications Test
  • Conduct Disorder
  • Continuum Approach
  • Cooperative School and College Ability Test
  • Crystalized Intelligence (Crystallized Abilities)
  • Das–Naglieri Cognitive Assessment System (Cognitive Assessment System; CAS)
  • Developmental Disorder (Developmental Disability)
  • Developmental Neuropsychological Assessment, Second Edition (NEPSY-II)
  • Deviation IQ
  • Diagnosis and Remediation (Remedial Learning)
  • Diagnostic and Statistical Manual of Mental Disorders (DSM)
  • Diagnostic Tests (Diagnostic Assessments)
  • Differential Ability Scales (DAS)
  • Differential Aptitude Tests
  • Dual-Process Theory of Intelligence
  • Dyscalculia
  • Dysgraphia
  • Dyslexia
  • Dysnomia
  • Dyspraxia
  • Educable Mentally Retarded (Educable Mentally Handicapped; EMH; EMR)
  • Educational Therapy
  • Emotional and Behavior Disorders (Behavior and Emotional Disorders)
  • Emotional Intelligence
  • Exceptionality Metaphor
  • Fluid Intelligence (Fluid Abilities)
  • Flynn Effect
  • Functional Disorder
  • g (g Factor; General Intelligence Factor; Spearman’s G)
  • g-VPR Model
  • General Ability (General Mental Ability)
  • General Intelligence
  • Generalizability Theory
  • Generalized Anxiety Disorder
  • Genius Metaphor
  • Giftedness Metaphor
  • Intellectual Disability (General Learning Disability; Cognitive Impairment)
  • Intelligence Metaphor
  • Intelligence Quotient (IQ)
  • Intermittent Explosive Disorder
  • International Classification of Diseases
  • Item Response Theory
  • Kaufman Assessment Battery for Children, Second Edition (KABC-II)
  • Kulmann–Anderson Measure of Academic Potential
  • Language Processing Disorder
  • Learning Disability (Specific Learning Disability)
  • Learning Disorder (Learning Difficulty)
  • Level I–Level II Theory
  • Luria-Nebraska Neuropsychological Battery (LNNB)
  • Marginal Intelligence
  • Medical Model
  • Mental Disease
  • Mental Disorder (Mental Illness; Psychiatric Disorder; Psychiatric Illness; Psychological Disorder)
  • Mentally Retarded (Mentally Handicapped)
  • Mixed Ability (Differently Abled)
  • Mixed Ability Grouping
  • Movement Disorder (Motor Disorder)
  • Multidimensional Aptitude Battery II (MAB II)
  • Nonverbal Learning Disorder
  • Norm
  • Normal (Normality)
  • Normal Distribution (Bell Curve; Gaussian Distribution; Normal Curve)
  • Normalism (Normism)
  • Normative (Normativity)
  • Norming
  • Obsessive-Compulsive Disorder (OCD)
  • Ohio State Psychological Examination
  • Oppositional Defiance Disorder
  • Organic Disorder (Organic Disease)
  • Organicism (Organic Approach)
  • Overachievement (Achievement Above Predicted Expectations)
  • PASS Theory of Intelligence
  • Perceptual Deficit (Perceptual Defect)
  • Performance IQ
  • Physiological Paradigm
  • Post-Traumatic Stress Disorder (PTSD)
  • Potential Metaphor
  • Primary Abilities Test (Primary Mental Abilities Test)
  • Professional Aptitude Test
  • Profound Mental Retardation
  • Psychoeducational Diagnostician
  • Psychogenic Disorder
  • Psychometrics (Psychometric Psychology; Psychometry)
  • Psychopathology
  • Pull-Out Program
  • Quickness (Delayed; Slowness; Retardation) Metaphor
  • Race Norming
  • Radex Model of Intelligence
  • Ratio IQ
  • Raven’s Progressive Matrices (RPM)
  • Reliability Theory
  • Reynolds Intellectual Assessment Scales (RIAS)
  • s (s Factor; Special Factor; Specific Factor; Spearman’s S)
  • Scholastic Aptitude Test
  • School Refusal (School Avoidance)
  • Sensory Processing Disorder (Sensory Integration Dysfunction)
  • Separation Anxiety Disorder (SAD)
  • Sharpness, Acuity (Dullness) Metaphor
  • 16 Basic Desires Theory
  • Smartness Metaphor
  • Social Anxiety Disorder (Social Phobia)
  • Social Intelligence
  • Social Quotient (Social Intelligence Quotient)
  • Spatial Ability / Spatial Reasoning
  • Special Child
  • Special Education
  • Special Needs
  • Specific Abilities (Special Aptitudes)
  • Standard Error of Measurement
  • Stanford–Binet Intelligence Scale, Fifth Edition (SB5)
  • Stereotypic Movement Disorder
  • Strength (Weakness) Metaphor
  • Structure of Intellect Theory
  • Supernormal
  • Talent Metaphor
  • Three-Ring Conception of Giftedness
  • Three-Stratum Theory
  • Tracking (Streaming; Phasing)
  • Trainable Mentally Retarded (Trainable Mentally Handicapped; TMH; TMR)
  • Two-Factor Theory [of Intelligence]
  • Underachievement
  • Unspecified Intellectual Disability (Mental Retardation, Severity Unspecified; Unspecified Mental Retardation)
  • Verbal IQ
  • Vineland Adaptive Behavior Scales
  • Wechsler Adult Intelligence Scale, Fourth Edition (WAIS-IV)
  • Wechsler Intelligence Scales for Children, Fifth Edition (WISC-V)
  • Wechsler Preschool and Primary Scale of Intelligence, Fourth Edition (WPPSI-IV)
  • Woodcock–Johnson Tests of Cognitive Abilities, Fourth Edition (WJ-IV)

Map Location

Please cite this article as:
Davis, B., & Francis, K. (2022). “Medical Model of (Dis)Ability” in Discourses on Learning in Education.

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