L09 Intelligence: Measuring Mental Performance

What Is Intelligence? - review

1. Psychometric approach: Focus on measuring intelligence through standardized tests. 2. Information-processing/Piagetian approach: Emphasizes how intelligence develops and cognitive processes. • Key Difference: Product-oriented (what we can measure) vs. Process-oriented (how we solve problems).

Psychometric views - review

• IQ tests do not measure potential, more of performance

• does not measure creativity, emotional intelligence, cultural knowledge

Psychometric Views on Structure of intelligence

• Singular-component theory: Proposes intelligence is one unified trait.

• Multicomponent theories: Intelligence involves multiple abilities (combination of them). - how can we identify abilities that may correlate w each other?

  • Factor analysis: (statistical method) Identifies distinct cognitive abilities that correlate together. (using tasks)

  • correlation = association b/w 2 variables, but here we are grouping highly correlated variables into fewer broader categories

  • common underlying ability if grouped together..

Psychometric: Singular-component theory of intelligence

• Binet + Mental Age

• Binet = father of intelligence testing → one of earliest measures to test intelligence → to identify those who needed more support or with intellectual disabilities

• developed tasks relevant to population

• he believed intelligence isn’t fixed, but can be improved w intervention (rationale for creating this measure)

• he introduced the idea of mental age, level at which a child functions intellectually (different from biological age)

Psychometric Perspective: Multicomponent theories of intelligence

• Spearman & Thurstone - review

• Spearman among first researchers to use factor analysis to explore if intelligence is one or many abilities

• positive manifold - regardless of type of test, they are positively correlated

• g = like general intelligence that influences all tasks

  • e.g., if excelling in math + verbal reasoning, this suggests that child is influenced general mental factor

• special abilities, s = task-specific skills (strength only in verbal tasks, defining words + sentences at certain speed or skill, weak in reasoning = special ability in verbal tasks)

• Thurstone - verbal comprehension = ability to define words, word fluency, number facility (add + subtract mentally), spatial visualization (mentally rotate 3d shape), associative memory (remembering friend’s bday because it falls on holiday), perceptual speed (ability to spot differences b/w similar picture in short amount of time), and reasoning (e.g., solving puzzles, or 2,4,6,8, what comes next) (equivalent to Spearman’s g)

  • argued these skills independent

  • current research = still correlated in some ways → Spearman’s g

Guilford & Cattell and Horn

Guilford’s structure-of-intellect model Classified intelligence into 180 primary mental abilities based on content, operations, and products.

• proposed that intelligence can be understood in 3 dimensions (operations, content, products), which each has subskills = 180 distinct intellectual abilities → more theoretical, didn’t gain much attention (not strongly supported w empirical evidence)

• later researchers found that abilities correlated instead of as independent constructs → not 3 distinct dimensions, can be correlated

Cattell and Horn: Distinguished between (important work for developmental psych)

• Fluid Intelligence (Gf); problem-solving in new situations

  • using reasoning rather than previous knowledge to solve problems (e.g., pattern recognition, abstract reasoning, puzzles, rules) → less influenced by education + culture (peaks in early adulthood, declines w age)

• Crystallized Intelligence (Gc); knowledge from past experiences (acquired thru education + life experiences).

  • vocab, general knowledge → as experiences increase w age, knowledge increases (knowledge remains stable until later adulthood)

Hierarchical Models and Carroll’s three Stratum theory

• Hierarchical models of intelligence - proposes that intelligence can be broken down to broad general abilities + neuro-specific abilities organized into specific structure

• Carroll’s three-stratum theory of intelligence organizes these abilities in a hierarchy.

  • One general factor (g) (of intelligence)

  • PLUS broad abilities

  • PLUS narrow specific skills - thurstone was also right (review)

  • called integration model

Hierarchical Models and Carroll’s three Stratum theory

• g = overall mental ability influencing performance across all tasks

• second = broad cog abilities - fluid + crystallized intelligence, etc.

  • not all broad relate to g, fluid intelligence greatly related to g, but auditory perception + processing speed are more specialized → John Carroll’s three-stratum hierarchical model of intelligence. Second-stratum abilities are arranged from left to right in terms of their decreasing correlation with g. So fluid intelligence and the reasoning it supports (e.g., quantitative reasoning) are more closely associated with general mental ability g than are auditory perception, cognitive speed, and the third-stratum skills that these abilities support.

• third = specific abilities making up each broad abilities

CHC Theory (Cattell-Horn-Carroll): CHC Theory: The Modern Hierarchical Model

Builds on Carroll’s Three-Stratum theory

• Carroll - overall structure of intelligence

• g, broad, specific

Integrates Cattell & Horn’s Fluid (Gf) & Crystallized (Gc) model

• id + describing broad abilities especially the distinction b/w fluid abilities + crystalized intelligence

• CHC combines these 2 perspectives, kept hierarchal structure but includes both fluid + crystalized

• Retains hierarchical structure: – g (general intelligence) – Broad abilities – Narrow skills ▪

• Currently the dominant framework in intelligence testing → considered a standardized test + most widely used

Information-processing perspective - review

Sternberg’s Triarchic Theory

• criticized for being too narrow → doesn’t tell how knowledge is acquired, retained → how is information used in problem solving

• Gardner’s Theory of Multiple Intelligences

traditional tests do not measure traits (common sense, social competence, emotional intelligence, creativity etc) → cog processes underlying intelligence (how child approach task, strategies used, efficiency of info processing)

Sternberg’s triarchic theory - review first part

a. Contextual Component: Practical intelligence; adapting to, shaping or selecting environments. (to better suit their strengths)

• intelligence depends on context, and may vary across cultures

• reflects a real-world ability, not testable (e.g., punctuality in NA meetings would be respectful + professional; in social gatherings - more flexibility for lateness + wouldn’t make difference for the event, like Latin cultures)

b. Experiential Component: Response to novelty and automatization.

• how experience would influence task performance

• two types of performance: responses to novelty (new tasks require active + conscious reasoning), automation(is this the word)? (how efficient at familiar task, less conscious effort needed)

• for intelligence tests, it must be equally familiar/unfamiliar across all cultural groups to be fair to avoid bias (otherwise reflects familiarity over ability)

c. Componential Component: Information-processing skills used in problem-solving.

• argued must examine mental processes used to generate answers

• how problem was analyzed, strategies used, etc (e.g., math problem - lose points for process not just for answer)

Gardner’s theory of multiple intelligences

• argued that intelligence is not only one general ability, but rather people display 9+ distinct intelligences

  • Linguistic - language use + meaning (poets, writers, lawyers → to express, to defend)

  • Logical-mathematical - reading recognizing patterns, solving mathematical problems (IQ/standardized test emphasizes this)

  • Spatial - ability perceive spatial problems (manipulate images) (e.g., architects, engineers, artists)

  • Musical - sensitive to pitch, rhythm, melody

  • Body-kinesthetic - ability to use body in skillful way to achieve goals/express ideas (gymnasts, athletes, even surgeons for fine motor skills)

  • Interpersonal - ability to understand others

  • Intrapersonal - being aware of internal states (strengths, weaknesses)

  • Naturalist - sensitivity to patterns in nature (plants, animals) (biologists, anthropologists)

  • Existential - sensitivity to deep life, death, meaning questions

• Individuals may display relative strengths and weaknesses across intelligences

  • also abilities are separate enough that they can be developed separately

• Evidence for Multiple Intelligences

  • Savant syndrome - extraordinary ability in a specific area but not others

  • Selective brain injuries - damage may affect language but not other areas

How Is Intelligence Measured?

• Early goal: Identify children needing academic support.

• First tests focused on mental age.

• Modern tests use norms and deviation IQ. (instead of using Binet + Simon’s mental age) - comparison w others of same age

• Intelligence tests continue to evolve. - more difficult to obtain measure that would test all abilities (working towards measuring beyond intelligence)

Stanford-Binet Intelligence Scale

• Revised from Binet & Simon’s original test - for American students

  • Introduced IQ (Stern, 1912): IQ = (Mental Age ÷ Chronological Age) × 100

  • IQ of 100 → mental age ~ chronological age

• Modern versions use deviation IQ → compare individual scores to others of same age in representative sample

• Measures verbal reasoning, quantitative reasoning, visual–spatial reasoning, short-term memory → measures abilities key to academic success

The Wechsler scales - review

• test developed b/c earlier tests relied too heavily on verbal skills (disadvantage to those who speed language as second language, intellectual disabilities, hearing issues)

• Wechsler Preschool and Primary Scale of Intelligence - Fourth Edition (WPPSI-IV). For younger children, from 2 years 6 months to 7 years 7 months.

• Wechsler Intelligence Scale for Children - Fifth Edition (WISC-V). For older children, specifically those aged 6 years to 16 years 11 months.

• Includes both verbal and nonverbal (performance) subtests

• Provides Full-Scale IQ + index scores: verbal comprehension, Perceptual reasoning, Working memory, Processing speed

The Kaufman Assessment Battery & Dynamic Assessment

Newer approaches to intelligence testing reflect modern theories

The Kaufman Assessment Battery for Children (K-ABC):

• Based on information-processing theory.

• Emphasizes understanding cognitive processes (to process info) rather than just intelligence outcomes. → more emphasis on fluid intelligence + tasks measuring measures simultaneous & sequential processing, planning, learning.

Dynamic assessment:

• Linked to Vygotsky’s Zone of Proximal Development → Evaluates learning potential (how well children learn when given guidance/scaffolding)

• Pre-test → Guided instruction → Post-test

  • intervention model → views intelligence not as fixed ability (review)

The Bayley Scales of Infant Development

Assessing infant intelligence (2 to 30 months)

• Motor scale (e.g., gross and fine motor skills) - sitting, walking; fine - grasping

• Mental scale (e.g., cognitive, language social skills) - reaching hidden object, ability to respond to name when called

• Behavior Rating Scale (attention, emotion, regulation, engagement during testing)

• Provides Developmental quotient (review)

  • DQ is a poor predictor of later IQ

Stability of IQ Across Childhood

How stable are IQ scores across childhood? → IQ score at age 8 correlates with IQ scores at age 18 (0.70). (but doesn’t mean IQ is fixed)

• Stability increases after early childhood.

• Many children show meaningful fluctuations.

  • Changes are often systematic, not random.

  • Environment plays a major role. (children raised in intellectually stimulating + supportive envs correlated w higher IQs (w/ poverty - decline in IQ over time)

• Cumulative deficit hypothesis:

  • Long-term exposure to disadvantaged environments can progressively lower intellectual performance → (even minor) chronic env disadvantages, effects accumulate + gradually weaken intellectual development

  • performance shaped by environments we are exposed to

Cultural Influences on Intelligence

Cultural Influence:

• Intelligence is not defined the same way across cultures. (standardized intelligence tests developed in western may not capture norms of intelligence across diff culture)

• Different cultures emphasize different cognitive skills.

Examples (just know what is discussed in lec)

• In Kenya, children with greater practical knowledge (e.g., navigating social situations and solving real-life problems) is more emphasized as a marker of intelligence compared to abstract reasoning

  • herbal medicine to treat illness → children didn’t score highly on traditional academic tests

  • practical knowledge + academic intelligence were found to be weakly correlated → intelligence depends on environmental demands + support (supports Sternberg idea, intelligence not just focused on practical knowledge; reviews)

• In certain Indigenous Australian communities, visual-spatial memory may be more developed due to the importance of navigating large territories without traditional maps.

  • strength in visual memory → can navigate environments well, showing how culture shapes which cognitive abilities that become well developed

Standardized Western IQ tests may not fully capture these abilities. (since they emphasize verbal, mathematical reasoning over spatial skills)

SES and Cognitive Development

Socioeconomic Status (SES):

• SES strongly influences cognitive development (Access to education, language exposure, healthcare, and enrichment matters varies with SES; although resilient children may sometimes excel in harsh conditions)

• Differences can widen over time

Example (UK study):

• At age 2: Low-SES children scored by 6 IQ points lower.

• By age 16: The gap nearly tripled

Flynn Effect:

• IQ scores rose by 3 points per decade across generations.

• Linked to improved education, nutrition, and cognitive stimulation.

Testing Bias and Language

Language and Testing Bias

• Traditional IQ tests reflect Western, middle-class values.

• Verbal tests may disadvantage bilingual or non-English-speaking children (may perform low on verbal IQ test → doesn’t mean child is intelligent but they are not proficient in language enough to understand + perform well at tasks, lead to non-verbal assessments)

Non-verbal Assessments, such as pattern recognition, spatial reasoning, and analogical reasoning, are dependent on language.

• Kaufman’s Brief Intelligence Test (K-BIT)

• The Raven’s Progressive Matrices

Monolingual vs. Bilingual: Bilingual students may show cognitive flexibility advantages, but verbal tests can underestimate their ability

What Do IQ Tests Predict?

• Academic achievement (r = 0.50 - 0.66) → moderately correlated, meaning it does partially explains grade variability, but there are many factors such as motivation, habits, personality, family support, among others, which affect IQ scores

• Educational attainment

• Occupational status (moderate relationship)

• Not perfect predictors of life success (physical health, lifestyles, etc. but not happiness / success)

• IQ predicts performance - not destiny.

Gifted Programs: Identification and Equity

• Giftedness historically defined as IQ ≥ 140 (Terman) → genetic studies of genius (followed children who have such IQ) (stereotype that are socially awkward, weak → incorrect they are outgoing + healthy) (but high IQ doesn’t correlate w great achievements because it depends on creativity, motivation, etc. .. acceptable achievements)

  • Today: High IQ + domain-specific talents (music, art, science, leadership)

• Identification methods:

  • Standardized IQ tests (e.g., WISC, NNAT - measures reasoning w visual patterns to reduce influence of language proficiency)

  • WISC looks at Academic performance, Teacher recommendations

  • Multiple measures/universal screening → assess everyone rather than specific children to make testing more equitable

• Programs: enrichment, acceleration, specialized classes

• Challenges: (concerns about equity (those in gifted programs often come from high SES + have more opportunities for gifted screening) → may underidentify more resilient, marginalized children who have less opportunity to show their strengths)

  • SES and cultural bias in identification

  • Access to private testing

  • Underrepresentation of minority and low-SES students

  • Social-emotional concerns (perfectionism, isolation)

Intelligence in Children with Special Education Needs

• learning + intellectual disabilities

• mental health disorders

• Learning Disabilities:

  • Uneven cognitive profiles → e.g., individual w dyslexia may have excellent problem solving abilities but struggle w reading due to phonological processing difficulties

  • May show strengths in some domains

• Intellectual Disabilities

  • IQ < 70 + deficits in adaptive functioning (communicating, self-care, etc.) → both criteria required for diagnosis

• Mental Health Disorders

  • Anxiety, depression → affect processing speed & attention (as well as motivation, temporarily)

• IQ = estimate of performance at one time

• twice-exceptionality (2e): gifted + learning disability (strength can mask weakness or vice-versa, making IDing more challenging) - masking effect- review

Compensatory Education: Head Start

• what happens if we change the environment?

• Goal: Reduce effects of early socioeconomic disadvantage

• Head Start (U.S.) & Canadian adaptations

• Aboriginal Head Start (culturally grounded, community-led, family involvement)

• Why Canada focused on Indigenous programs: Long-standing structural inequities (colonization, residential schools, systemic underfunding of health systems, education); Barriers to early learning opportunities; Emphasis on culturally responsive early childhood education

• Early Findings: Short-term IQ gains (8-10 points); IQ gains often faded in elementary school (“fade-out effect”)

• Key Debate: Arthur Jensen: program “failed” because IQ gains faded → Developmental view: IQ is only one outcome (not because intervention failed, we miss broader env picture we aim to look at) - review last bit

Long-Term Effects of Early Intervention

Longitudinal studies show:

• Higher academic achievement

• Less grade retention

• Lower special education placement/need

• Higher high school completion

• Lower delinquency & teen pregnancy

• Greater employment

• IQ gains may fade, but life outcomes improve.

The Carolina Abecedarian Project

• tested whether earlier + longer intervention is more effective:

• Began at 6-12 weeks of age (infancy) → Intensive, full-day intervention (5 years)

• Participants: high-risk, low-income infants

• Results:

  • IQ advantages maintained into adolescence

  • Academic gains

  • Health benefits into adulthood

• Video

  • look at current capabilities → gradually increase complexity of tasks

  • IQ scores compared w those without intervention (no difference in early months, but at 15 months, the way children saw the world different - more language fluency, efficiency); by 2-3 yrs, there were major differences)

  • at 5 yrs, after attending school they were tested → higher academic performance and careers)

  • IQ was a measure to see change occurring and that early intervention helped improve learning

Two-Generation Interventions: Changing the Family System

• Target both children and parents

  • Parenting coaching and social support

  • Educational and vocational training for parents

  • improving parenting, lowering stress levels, providing more opportunities → better well-being and gives them more chances in supporting children’s environment

• Long-term change in parenting practices (not just affected IQ of children)

• “Diffusion effect”: younger siblings benefit indirectly (even though they never participated in programs)

Creativity + Thinking Processes

• Creativity → ability to generate Novel ideas that are Appropriate and have useful solutions, Valued by others

• Thinking Processes

  • Convergent thinking → one correct answer (IQ tests measure this)

  • Divergent thinking → multiple possible solutions (creativity involves more of DT)

• Key Point: Divergent thinking is only modestly correlated with IQ.

• High IQ ≠ high creativity (and moderate IQ doesn’t prevent creativity)

Sternberg & Lubart: Investment Theory of Creativity

Core Idea:

• Creative individuals “buy low and sell high” in the world of ideas.

• Invest in novel or unpopular ideas + Persist despite resistance

• Develop ideas until they become valued and gain attention

Creativity requires a convergence of six resources: Intellectual skills, Knowledge of domain being argued for, Cognitive style, risk-tasking Personality, intrinsic Motivation, Supportive environment

Creativity = interaction of person + context support, not just a reflection of a single ability (emerges from multiple interacting systems)

Applying Developmental Themes to Intelligence & Creativity - review

• Active child

  • Curiosity and engagement shape opportunities

• Nature + nurture

  • Genetics and environment both influence IQ and creativity

• Stability & change

  • IQ becomes moderately stable after early childhood

  • Infant DQ does not strongly predict later IQ

  • Early intervention can alter developmental trajectories

• Holistic development

  • Intelligence influences academic, social, emotional, and occupational outcomes

Intelligence and creativity reflect dynamic interactions across development, not fixed destiny.

Research question

• does education increase intelligence

• or does more intelligent students stay in school more

• study = meta-analysis, using quasi-experiments, longitudinal studies results, natural experiments, school entry cutoff studies

Q.1 What is the central developmental claim being made? (What is being argued about development, change, or risk?)

Education has a causal effect on intelligence.

• IQ is not fully fixed.

• Years of schooling contribute to measurable increases in cognitive ability (later IQ).

• intelligence is flexible

• Development of intelligence is shaped by environmental input over time (provided by schooling) (exposed to numeracy + literacy, abstract reasoning, training of meta-cognition in school settings + problem-solving environments) → improves executive functioning

Q.2 What type of evidence is used? (Correlational, longitudinal, experimental, animal models, review?)

• Natural experiments (changes in compulsory schooling laws)

• Longitudinal studies

• School entry cut-off studies

• Policy-based quasi-experimental designs

Q.3 What does the article not claim? (Where are the limits, cautions, or unresolved questions?)

It does NOT claim that: ▪ Education completely determines intelligence ▪ Genetics are irrelevant ▪ IQ increases infinitely with schooling ▪ All cognitive do

Q.4 How would this evidence be misused in the media or public discourse? (Correlation vs causation, overgeneralization, determinism)

▪ Overstating effects: School makes everyone equally intelligent. ▪ Policy oversimplification: Assuming more years automatically equal better thinking without quality instruction. ▪ Ignoring Nature-Nurture interaction: Framing it as pure nurture versus nature. ▪ Political misuse: Using findings to dismiss structural inequality

Q.5 Which developmental lens or theory helps interpret these findings best? (Biological, learning, cognitive, sociocultural, transactional)

Transactional OR Developmental Systems

Case Analysis

• Identify which intelligence theory explains it best, justify choice of theory, predict how IQ might change over time

• Case A: A child navigates complex social dynamics in a refugee camp but scores average on IQ tests

  • Sternberg practical intelligence + also can be Gardner interpersonal knowledge

  • social adaptation, interaction, navigation (not measuring analytical ability) → interpersonal, practical intelligence

  • refugee camp has enriched environment; over time if in enriched env, IQ score increases; limited environment - IQ stays average

• Case B: A student memorizes formulas easily but struggles to apply them in new situations.

  • memorization = crystallized knowledge, but child struggles with fluid knowledge (likely that child has strong g, but weak gf)

  • over time if child trained on reasoning strategies, IQ would increase with improvements w fluid knowledge (need more practice + exposure to experiences)

• Case C: A teenager from a low-SES background improves dramatically after entering an enriched school environment.

  • cumulative deficit hypothesis → low SES puts you at significant disadvantage which may suppress cognitive performance; shows significance of plasticity (how brain can change depending on environment)

  • over time, IQ would increase if child is continually placed in enriched env; but if this env is removed, IQ score would drop