Intellectual Development Disorder (Final) Flashcards
Measuring Intelligence and IQ
In the early 20th century in the West, IQ testing was seen by eugenicists as a way to identify people who they thought should not be allowed to have children. Subsequent development of IQ tests was racist, testing cultural based knowledge and test-taking proficiency. During this time, people identified as having lower intellectual functioning were put in institutions and sterilized without consent.
What is intelligence? Cognitive abilities vs Intelligence
Cognitive abilities: Are a set of mental processes which improve and degrade over the course of the lifespan. Intelligence: Refers to a measured quantity which summarizes a person’s ability to apply knowledge and skills.
The Psychometric Approach to Intelligence (Crystallized vs Fluid Intelligence)
Spawned the development of standardized tests of intelligence. Contrasted crystallized vs. fluid intelligence. Crystallized: Your use of knowledge that you might acquire through things like school, parents, and other life experiences. How many facts do you know? Fluid intelligence: Ability to use your mind to solve novel problems, often associated with raw processing power. Crystallized intelligence continues to increase into old age, whereas fluid intelligence peaks around young adulthood and beings to increase around middle age.
The Psychometric Approach: Mental Age
Level of age-graded problems that the person is able to solve.
The Psychometric Approach: Hierarchical views of intelligence
General ability (variance in g): Unmeasured characteristics. Everyone has a g, but can’t really measure it. So we try to approximate.
Broad abilities (cognitive domain variance): We have different cognitive domains. E.g. Domain 1 = crystallized intelligence. Domain 2 = fluid intelligence. etc. In this case, crystallized and fluid intelligence make up your general intelligence.
Specific abilities (specific test and error variance): Probably don’t have a direct or overall test of fluid or crystallization intelligence either, so we create specific tests / indicators that tell us something about them.
The arrows go top (g) to down (specific abilities) because the actual reason we perform well on certain tasks is due to our underlying intelligence.
The Psychometric Approach: Binet’s test
Stanford-Binet intelligence scale. Gives you an overall IQ score. Score on tasks feed into score on a bunch of domains, which gives you a single IQ score.
The Psychometric Approach: Wechsler Scales (IQ)
Different tests based on the age bracket of the person.
Hierarchical view of Intelligence - reflected in Wechsler Intelligence Scales for Children (WISC)
Primary Index Scales:
1. Verbal Comprehension (Similarities, Vocabulary)
2. Visual Spatial (Block Design, Visual Puzzles)
3. Fluid Reasoning (Matrix Reasoning, Figure Weights)
4. Working Memory (Digit Span, Picture Span)
5. Processing Speed (Coding, Symbol Search).
Each name in brackets is a specific task that feeds into our five primary index scales, which feed into our g or our calculation of an IQ score. If you have specific concerns about a particular area of an intellectual functioning, you might chose to give more tests in that area.
The Psychometric Approach: Test norms
Standards of normal performance expressed as average scores and the range of scores. Based on the performance of a large, representative sample.
The Stability of IQ Scores during Childhood
Strong relationship between early and later IQ starting at age 4. But individuals might show ups and downs. Closer administration times are more highly correlated. As a child gets older, their correlation between their assessments gets stronger.
Reasons Behind Racial-ethnic Disparities
Most studies find racial and ethnic differences in IQ scores. Why? Bias in the test. NOT due to genetic differences between groups - race is socially constructed not genetic. Environmental differences among groups. Stereotype threat.
Factors Accounting for Racial Differences: Differences in environment
When you account for things like family income home environment and other things associated withe env-low SES differences, Black White disparities in IQ go down to ~9 point differences. Differences still persist that may be due to other factors.
Gardner’s Theory of Multiple Intelligences
Gardner rejects IQ score as a measure of human intelligence. He argues for 8 different dimensions of intelligence (multiple intelligences). Not hierarchical. Key thing: He asks how are you smart (in what domains are you smart).
Sternberg’s Triarchic Theory of Intelligence
- Practical Intelligence (street smarts)
- Creative Intelligence (novel problems)
- Analytic Intelligence (selecting mental processes that will lead to success).
All add up to your overall intelligence. Successful intelligence idea came after triarchic theory. Under Sternberg’s theory, successful intelligence allows one to: Establish and achieve reasonable goals, optimize your strengths and minimize weaknesses
Under Sternberg’s theory, successful intelligence allows one to:
- Establish and achieve reasonable goals.
- Optimize your strengths and minimize weaknesses.
- Adapt to the environment.
- Use all three components of intelligence.
DSM-5 - Measuring Intelligence and IQ
In DSM-5, Intellectual Developmental Disorder is defined by adaptive functioning, rather than strictly by intellectual functioning and IQ. This is a change form DSM-IV. One reason they moved away from a stricter reliance on Iq is the Flynn Effect. When considering treatment, focus is on integration and building strengths and independence.
DSM-5: Measuring Intelligence and IQ - The Flynn Effect
A phenomenon where IQ scores have risen about 3 points per decade. So the test makers re balance the IQ test every decade to keep the mean IQ at 100 SD. This might lead to some people scoring lower then they would otherwise for a little bit.
Core Features of Intellectual Developmental Disorder: DSM-5-TR
Independence and autonomy can look very different in different places. You need all 3 criteria of deficits in intellectual functioning.
1. Deficits in intellectual functioning including reasoning, problem solving, planning, abstract thinking, judgment as confirmed by both clinical assessment and individualized, standardized intelligence testing.
2. Deficits in adaptive functioning that result in failure to meet developmental and sociocultural standards for personal independence and social responsibility; functioning is limited in one or more activities of daily life across multiple environments.
3. Onset during developmental period.
Level of Severity Based on Adaptive Functioning: Mild
Applies to about 85%. Typically not identified until elementary school years. Low SES is a risk factor. Differential access to resources may result in not stimulating cognitive development as much as people with greater access to resources (the more impoverished you are the more likely you are to have mild IDD).
Level of Severity Based on Adaptive Functioning: Moderate
Applies to about 10%. Get identified earlier because impairments are easier to see and more serious in nature (preschool years). More profound intellectual difficulties. More trouble with receptive language and expressing yourself. Adults with IDD would be functioning around the primary school level (big difference from mild to moderate). Applies to many people with Down syndrome.
Level of Severity Based on Adaptive Functioning: Severe
Apples to about 3%-4%. Often associated with clear organic cause (something that can be identified even as early as during pregnancy). Often needed supervision at all times. Need a lot of support in activities in daily living / practical skills. Usually identified at very young age.
Level of Severity Based on Adaptive Functioning: Profound
Apple to about 1%-2%. Very limited conceptual skills, language, understanding of non-verbal communication. Dependent on others for almost all aspects of their care. Usually identified in infancy. Almost always associated with clear organic cure and often co-occurs with severe medical conditions.
Domains of Adaptive Functioning
Conceptual Skills: Receptive and expressive language, reading and writing, money concepts, self-directions.
Social skills: Interpersonal, responsibility, self-esteem, gullibility, follows rules…etc.
Practical skills: Personal activities of daily living such as eating, dressing, mobility, and toileting. Instrumental activities of daily living such as preparing meals, taking medication, using the telephone, managing money…etc.
Prevalence of IDD overall
Community prevalence estimates range from 1%-3%. Cultural and contextual differences: More prevalent in lower SES groups. Differences any apparent for mild ID. Gender differences: Slightly more males than females (mainly for mild ID).
Inheritance and the role of the environment (Genotype vs Phenotype)
Genetic influences are potentially modifiable by the environment. Genotype: a collection of genes that pertain to intelligence. Phenotype: the expression of the genotype in the environment (gene-environment interaction). The heritability of intelligence is about 50%. Major environmental variations affect cognitive performance and social adjustments in children from disadvantaged backgrounds.
Etiology: Organic
Includes chromosome abnormalities, single gene conditions, and neurobiological influences. Tend to be moderate, severe, and profound. Prevalence comparable across SES groups.
Etiology: Cultural / Familial
Does not have a clear cause. Includes family history of intellectual Developmental Disorder, economic deprivation, inadequate child care, poor nutrition, and parental psychopathology. Tend to be mild cases (aka most cases). Higher rates in lower SES families.
Specific Organic Syndromes: Chromosomal abnormalities
Most common cause of severe ID. Down syndrome (chromosome 21, most cases are random events). Prader-Willi and Angolan (chromosome 15, most cases are random events). Fragile-X syndrome (X chromosome, inherited).
Specific Organic Syndromes: Single-gene problems
Phenylketonuria (PKU; inherited): Cannot metabolize amino acid phenylalanine, rising levels are toxic and impact intellectual development).
Specific Organic Syndromes: Neurobiological injury
Prenatal (e.g. Fetal Alcohol Syndrome). Perinatal (E.g., anoxia at birth). Postnatal (e.g., head injury).
Comorbidity: Down syndrome Language and Social Behaviour
15-20% of population with ID has Down Syndrome. Characteristics displayed with Downs Syndrome: The underlying symbolic abilities of children are believed to be largely intact. There is considerable delay in express language development; expressive language is weaker than receptive language.
Comorbidity: Characteristics Displayed With Down syndrome
Fewer signals of stress or desire for proximity with primary caregiver. Delayed, but positive, development of self-recognition. Delayed and aberrant functioning in internal state language: reflects emergent sense of self and others.
Comorbidity: Emotional & Behavioural Problems
Rate is three to seven times greater than in typically developing children - largely due to limited communication skills, additional stressors, and neurological deficits. Most common psychiatric diagnoses: Impulse control disorders, anxiety disorders, and mood disorders. Internalizing problems and mood disorders in adolescence are common. ADHD-related symptoms are common. Pica is seen in serious form among children and adults with ID (eating non-food things). Self-injurious behaviour (SIB) is more common in people with IDD.
Comorbidity: Other Physical and Health Disabilities
Health and development are affected. Degree of intellectual impairment is a factor. Prevalence of chronic health conditions in ID population is much higher than in the general population. Life expectancy for individuals with Down syndrome is now approaching 60 years.
Prevention: Prenatal care
Access to education can potentially reduce the risk of neurobiological injury (pregnant people should not be eating these foods, or doing these things…etc). Increasing gestation time helps reduce likelihood of child being born with IDD. Plan for uncomplicated delivery.
Prevention: Early childhood care and education
Safe and stimulating environments. Safe: Lead paint. Stimulating: Education programs - major focus on speech and communication, early intervention optimal, educational enrichment for low-SES youth.
Prevention: Educational Enrichment
Gap of 1500 words per hour between words spoken by parents with an advanced degree and parents who receive social assistance (lower SES). Has a huge effect over time.
30-million word gap Study
See a difference in quantity of words by SES and quality of language exposure matters too. Increasing quantity of language exposure is likely beneficial and would reduce disparities one early childhood language abilities. This is a systematic issue - we shouldn’t stigmatize lower SES families.
Carolina Abecedarian Project
Low-income families. Four cohorts of children recruited from 1972 and 1977. Randomly assigned as infants to receive a full-time educational intervention at a project-run childcare centre OR to be cared for at home or in another child care centre. Offered enriched environments from infancy through preschool (lasted 5 years): individualized educational program, focus on language, games. By age two, children who are receiving the program have higher test scores than children in control group, and thee difference were maintained over time. Their scores stay higher over a prolonged period of time - still saw differences at 21 years of age. A larger percentage of children in the intervention group went to college.
High Scope Perry Preschool Study
123 high risk preschoolers, 58 entered into new high quality preschool program, 65 got nothing. Study found that at age 40, participants who experienced the preschool program: were less likely to experience teenage pregnancy, more likely to graduate from high school, more likely to maintain employment and have higher earnings, less likely to commit crimes, more likely to own a home and car. Town also got a huge return on investment through this program.
Behavioural Approaches
Initially seen as a means to control or redirect negative behaviours. Association for Behaviour Analysis (ABA) Task Force advocates that: Each individual has the right to the least restrictive effective treatment and the right to treatment that results in safe and meaningful behaviour change.
Cognitive-Behavioral Therapy
Self-instructional training and metacognitive training. Verbal instructional techniques. Teaching the child to be strategical and meta-strategical: How to use strategies effectively and how to think about strategies (e.g., which strategy do I need in this situation).
Family-Oriented Strategies
Help families cope with the demands of raising a child with ID. Some ID children and adolescents benefit from residential care or out-of-home placement. The inclusion movement integrates individuals with disabilities into regular classroom settings - curriculum is adapted to individual needs.
