Intelligence TestingMelissa Stern

PSY 4930 October 3, 2006

What is Intelligence?

A loaded question . . . Ability to modify one’s behavior to meet

demands of the situation Abstract reasoning (using symbols or mental

representations) Capacity to acquire knowledge Problem solving ability

Definition of Intelligence

Common to many definitions of intelligence Knowledge-based thinking Apprehension Adaptive purposeful striving Fluid analytic reasoning Mental playfulness Idiosyncratic learning

Theories of Intelligence

Terman coined the term “Intelligence Quotient” (IQ) in 1916 Mental age/Chronological age

Spearman’s 2 Factor Theory (1927) Intelligence =

General factors (g) — “mental energy” E.g., abstract reasoning, problem solving

Specific factors (s) — less complex tasks E.g., motor speed, attention, v-m coordination, memory

Although originally a 2 factor theory, g is the only factor that accounts for correlations among intellectual abilities

Theories of Intelligence

Thurstone’s Multidimensional Theory (1938) Eight primary mental factors

Verbal, perceptual speed, inductive reasoning, number, rote memory, deductive reasoning, word fluency, space or visualization)

He eventually found that these factors correlated and later postulated a second-order factor similar to “g”

Multiple Intelligences?

MUSICAL INTELLIGENCE

Is it a type of an intelligence?

Or is it just special talents?

Discuss!

Theories of Intelligence

Cattell & Horn’s Fluid and Crystallized Intelligence (1966) Fluid intelligence=one’s inborn abilities largely

determined by genetics and biology Fluid intelligence develops through childhood and adolescents Examples: number/letter series, matrices

Crystallized Intelligence=acquired skills and knowledge Influenced by environment and culture Continues to develop over the lifespan Examples: vocabulary, general information

Some tasks measure both: Arithmetic reasoning

Theories of Intelligence

Piaget’s Developmental Theory Hierarchical model with four major periods of

cognitive development Sensorimotor period Preoperational period Concrete operations period Formal operations period

Correlations have been found between Piagetian tasks and psychometric scales of intelligence

A Modern View of Intelligence

Intelligence is an integrated construct including: Biological—dependent on genetics, brain

structure, physiological functioning of brain Cognitive—metacognition and ordinary cognition Motivational—magnitude, direction, and

disposition of individual Behavioral—behavior in academic, social, and

adaptive domains Genetically-determined intelligence is always

modified by experience

Environmental Influences on IQ

Factors that enhance IQ: Stimulating environment Good medical care/nutrition Parental involvement in learning Rich language environment

Factors that negatively impact IQ: Persistent poverty

Perinatal complications, inadequate stimulation in environment, lead exposure

Large family size Nutrition during gestation and early childhood

Heredity and IQ

“Heredity may limit a child’s potential, but environment permits their potential to be actualized” (Sattler, 2001, p. 180) We inherit genes, not an actual IQ

Genetics is only 1 factor affecting IQ (familial, educational, nonfamilial factors)

IQ can change, but it is difficult Does seem to go up on average about 4 points

between childhood and adolescence (develop problem-solving strategies over time)

The Bell Curve (1994)

Controversial book on the social ramifications of IQ stratification

The “Cognitive Elite” associate with other elite Physical separation from others

Make more money Live in different neighborhoods

The Bell Curve: Social Problems and IQ Poverty - IQ predicts poverty, even more than

SES in which people grow up Schooling - IQ increases risk of dropping out of

school and decreases chances of college degree Unemployment, Idleness and Injury - IQ is

associated with unemployment, frequent injury, or idleness (removing oneself from the workforce) 

Family - IQ is related to high rates of divorce, lower rates of marriage, and higher rates of illegitimate births 

The Bell Curve: Social Problems & IQ Welfare Dependency - IQ increases the

chances of chronic welfare dependency  Parenting - IQ of mothers correlates with

low birth weight babies, poor child motor skills and social development, and children’s behavioral problems 

Crime - IQ increases the risk of criminal behavior

Civility and Citizenship – those with IQ vote least often

The Bell Curve: Gender, Ethnicity & IQ Few gender differences were found

Males higher on spatial and quantitative Females higher on verbal ability

East Asians score highest, then European Americans, Hispanics, and African Americans

APA task force on IQ IQ can predict individual differences, but not necessarily

group differences Socioeconomic influences may play a role Cultural differences may affect education

emphasis on spirituality, harmony, movement, verve, affect, expressive individualism, communalism, etc.

IQ Tests and Culture

Culturally Biased Proponents of this view feel IQ tests are biased

against ethnic minorities and don’t take their sociocultural factors into account

Culturally loaded Proponents of this view feel IQ tests are

reflective of the knowledge and skills of the dominant society (those who created the test)

Pros and Cons of IQ Testing

Pros Cons

Reveals unknown talent Self-fulfilling prophecy

Standardized method of comparing children

Measures only processes needed for successful test performance

Excellent predictors of academic performance

Biased against ethnic minorities

Valuable for children with disabilities

Poor predictors of real-life situations

Predicts success in a wide variety of endeavors

Unconventional responses are penalized

Common IQ Misperceptions

IQ is innate IQ never changes IQ tests provide perfectly reliable scores All IQ tests measure the same thing IQ test scores are interchangeable

IQ tests vs. Achievement tests

IQ tests measure broader abilities IQ tests are more predictive of future performance Achievement tests (reading, math, etc.) are heavily

dependent on formal learning at home or school Achievement test scores change more readily Achievement tests assess mastery of factual

information; IQ tests assess ability to apply information in new ways

Common Intelligence Tests

Stanford-Binet Intelligence Scale Originally developed in 1916 Currently in the 4th edition

Wechsler Intelligence Scale (WISC) For children 6-16 years Currently in the 4th edition (2003)

Wechsler Preschool and Primary Scale of Intelligence (WPPSI) For children 3 years to 7 years, 3 months

Bayley Scales of Infant Development (BSID) For children aged 1 to 42 months Cognitive, Motor, and Behavioral scales

IQ Test example: WISC-IV

15 subtests (some of them are optional) Administration time varies from 1-3 hours Must be trained in order to administer – complicated rules Provides

Full Scale IQ--Global estimate of child’s general intellectual capacity/potential/level of cognitive ability and the relative standing compared to the normative population

Verbal Comprehension Index –verbal reasoning skills Perceptual Reasoning Index – nonverbal reasoning skills Working Memory –ability to attend to and hold information in

memory to formulate responses Processing Speed – speed of processing information Uses the deviation IQ (mean = 100, SD = 15)

WISC-IV Subtests

Block Design Similarities Digit Span Picture Concepts Coding Vocabulary Letter-Number Sequencing Matrix Reasoning Comprehension Symbol Search (Picture Completion) (Cancellation) (Information) (Arithmetic) (Word Reasoning)

Matrix Reasoning Example

WISC-III Subtests

VCI Similarities Vocabulary Comprehension Information* Word Reasoning*

PRI Block Design Picture Concepts Matrix Reasoning Picture Completion*

WMI Digit Span Letter-Number Sequencing Arithmetic*

PSI Coding Symbol Search Cancellation*

IQ Testing Considerations

Examiner variability (i.e., giving extra help, errors in administration, incorrect scoring, etc.)

Situational variability (i.e., on/off medications, Ritalin, fatigue, illness, hunger, etc.)

Individual subtest scores are not as reliable as the FSIQ and Indices

Qualitative observations are also important

Types of IQ

Ratio IQ First type of IQ Stern (1938) IQ = MA/CA x 100 Same IQ has different

meanings at different ages

Not used as often now

Deviation IQ A type of standard

score Mean = 100, SD =

15/16 Compares IQ to same

age peers Normal distribution WISC uses this