Intelligence & IQ Testing Flashcards
What is Intelligence?
- no clear cut definition
- many influential definitions:
Sensory Capacity (Galton)
Abstract Thinking(Binet & Simon)
General vs Specific Spearman
Fluid vs Crystallized(Cattle & Horn)
Multiple Intelligences (Gardener, Sternberg)
Sensory Capacity
- Galton
- gain intelligence & knowledge through the senses
- the better your sensory capacity, the more knowledge you can collect
- large scale sensory tests on 9000 people in a lab - ultimately found that sensory capacity is weakly correlated with intelligence
Abstract Thinking
- Binet & Simon
- French researchers
- developed first IQ Test
- instructed by French government to test where/ which students would struggle
- asked diverse questions
- to them: intelligence is the ability to think and reason abstractly
- found correlations between different skills/ abilities which all cumulated to abstract thinking
General vs Specific
- g or general intelligence: “strength of our mental engines”
- s or specific intelligence: particular ability in a narrow domain
- people have different mental strengths
Fluid vs Crystallized Intelligence
Fluid Intelligence
- capacity to learn new ways of solving problems
- increases with age & peaks in early adulthood
- flexible, adaptive
- logical problem solving, abstract reasoning
Crystallized Intelligence
- accumulated knowledge of the world
- increases with age
- related to personality trait: Openness to Experience
- general knowledge, vocabulary, product of educational and cultural experiences
- ex. Jeopardy Winners have extremely high crystallized intelligence
Multiple Intelligences
- Gardener, Sternberg
- people vary in their strengths
- Howard Gardner’s Theory of Multiple Intelligences: “Frames of Mind”
Sternberg’s Triarchuc Model
- Analytical
- Creative
- Practical
- this is often what people think of and is tested for
- argued creativity should be labelled independently as it is not related to analytical or practical
- the three are correlated to each other- are they truly independent or just have underlying characteristics or “g” that dictates people’s performances in different domains
What is Intelligence?
Intelligence consists of the abilities to…
- reason abstractly
- learn to adapt to novel environmental circumstances
- acquire knowledge
- benefit from experience
Biological Bases of Intelligence
Is having a larger brain related to higher intelligence?
- Yes! Small Positive Correlations between brain volume and IQ between +0.3 ad +0.4
Is this a causal relationship? In other words, does having a large brain CAUSE you to have higher intelligence?
- probably not causal because…
- third variable problem - Z causes increase in both X & Y (maybe nutrition?)
- exceptions to the rule - Albert Einstein had smaller brain than average (but parietal cortex was 15% larger (connected to spatial ability))
Intelligence may reflect efficiency of mental processing
-
intelligence and memory
- working memory tasks moderately correlated (+0.5) with IQ scores
- recall working memory is short term memory: able to store and manipulate about 7 things in mind
- working memory task: start at 500 and count backwards by 7 while trying to figure out meaning of a saying
-
intelligence and reaction time
- reaction time negatively correlated with intelligence (faster reaction times = higher intelligence)
Tetris
- reaction time negatively correlated with intelligence (faster reaction times = higher intelligence)
- persons with higher intelligence show…
- quicker reaction times
- less overall brain activity - people with high intelligence tend to have more efficient brains
- more improvement over time
Biological Bases of Intelligence
- prefrontal cortex is especially active during highly “g-loaded” tasks
- but other areas of the brain are also important (eg. parietal cortex - spatial reasoning)
- Central Theme: speed/ efficiency of information processing is related to intelligence
History of the Intelligence Tests
-
Binet-Simon Intelligence Scale - Alfred Binet & Theodore Simon
- government of France tasked them
- with the goal of identifying kids who needed help
- original goal of IQ Test was to help children
- series of tests focus on attention, memory > math, reading
-
Stanford-Binet IQ Test - Lewis Terman
- tested many people to find averages of IQs for age
- soon after IQ tests were developed, their use began to be abused - eugenicists loved the IQ test
- worry about “low IQ” in certain groups and the eugenics movement
- encouraged people with “good genes” to reproduce (positive eugenics) and discourage people with “bad genes” from reproduction (negative eugenics)
- forcible sterilization and immigration laws were more visible impacts on society
- 66,000 people were sterilized without any knowledge or consent because of worries about their IQ - including children!!! - 1950s ish era - mostly black community in bad socioeconomic situations
- gave IQ tests to people immigrating here IN ENGLISH - ultimately limiting immigration from certain parts of Europe
Kendi IQ Test Video - Ibram X Kendi
- said the person who first created SAT test or Lewis Terman who brought IQ Test to US were eugenicists
- LT put in book that these tests will prove that the test will prove that Latinos, Blacks and Women were intellectually inferior
WAIS - Wechsler Adult Intelligence Scale
- most commonly used IQ test for adults
- Consists of 15 subtests that give 5 scores:
- Overall IQ
- Verbal communication
- perceptual reasoning
- working memory
- processing speed
Intelligence Quotient (IQ)
IQ = [mental age/ chronological age] x 100
IQ test score: scores like an 11 year old
Mental age: 11 years old
Chronological age: 8 years old
IQ = [11/8] x 100
IQ score = 137
Flaw: mental age evens/ levels out at about 16 years old
- if you score 130 at 16, you will likely score around the same later in life
- this causes a decrease after 16
- Solution:
- deviation IQ
- how does this person deviate from average
Tests for Kids
- WISC - Wechsler Intelligence Scale for Children
- 6 - 16yo
- WPPSI - Wechsler Primary and Preschool Scale of Intelligence
- 2.5 - 7yo
Culture-Fair IQ Tests
- consist of abstract-reasoning items that don’t depend on language
- Raven’s Progressive Matrices: which is the final pattern in this series? - abstract tests
- goal is to reduce the use of language & culturally specific knowledge
Reliability of IQ Scores
Test-Retest Reliability: high
Adulthood
- IQ scores remain reasonably stable over long periods of time
- if you test someone when they’re 16 or 25 or 50, it would be very similar results
Infancy and Childhood
- Age 11 > Age 77 - IQ correlated +0.73 - high IQ scores at 11 were related to high IQ scores later in life
- IQ tests are not stable before age 2-3 years - poor predictors of adult IQ and overall outcomes
- exception: very low early IQ scores can signal intellectual disability
- IQ tests for very young children mostly assess sensory abilities & motor development
Stability of IQ
Infancy & Childhood
- visual habituation: how quickly does an infant become bored with a stimulus?
- infants who habituate faster (more quick to get bored of a stimulus) have higher IQ scores in adolescence
- correlation of 0.3 - 0.5 (small to moderate correlation)
- several reasons why habituation and IQ might be related:
- intelligent babies take in more information from novel stimuli more quickly
- infants who are interested in new things habituate faster AND learn more things → higher intelligence
- Not sure of the causal relationship here: do babies who habituate faster lead to higher IQ?
Validity of IQ: Predicting Life Outcomes
- recall validity is if we’re measuring what we think we’re measuring; many kinds of validity - in this case predictive validity
-
IQ predicts academic grades
- correlation is 0.5
- lower than 1.0 - what else contributes? study habits, attendance, stress, nutrition
-
IQ predicts occupational performance (correlations 0.5)
- how well you do in your chosen field
- depends on occupation - better predictor for jobs that we think of as needing higher levels of intelligence; like doctors
-
IQ predicts health outcomes
- IQ in childhood → adult morbidity (how likely you are to become ill of any cause) & morality (how likely you are to die of any cause)
- intelligence enhances learning, reasoning, problem-solving skills
-
health literacy: degree to which individuals have the capacity to obtain, process, understand basic health-related information and services needed to make appropriate health decisions
- ex. confusing warnings for drugs
-
health literacy: degree to which individuals have the capacity to obtain, process, understand basic health-related information and services needed to make appropriate health decisions
- relationship between IQ and health outcomes
- confound: poverty
- we know that socio-economic status is related to IQ scores
- it’s also related to (poor) health outcomes
- however, relationships hold up even when social class accounted for
Genetic & Environmental Influences
Family Studies
Twin Studies
Adoption Studies
Heritability: (number that reflects) how much is variation in a trait due to genetic contributions?
- how much the variation is dependent on genetic differences
- looking for how much IQ scores are related to genetics or environment
- only ever applied to a group of people, not 1 individual
Family Studies
- look at people who are all biologically related to each other - parents, siblings, cousins, etc - varying relationships
- if IQ is genetic, then IQ scores should be most similar between siblings
- IQs are more similar the more closely related family members are
- Siblings - correlation is 0.5
- Cousins - correlation is 0.15
- biological siblings reared/ raised together have more similar IQs than adopted siblings reared together
Twin Studies
- correlation of IQ between identical twins vs fraternal twins
- identical twins share 100% of genetics and the IQ correlation between them is +0.86 compared to fraternal twins share 50% of genetics had a correlation of +0.60
- higher correlation the more genetic information is shared
Determining Heritability
Heritability Coefficient, H
- an index of the heritability (amount of variation in a trait that is attributable to genetic factors)
- varies from 0 to 1 - no negative
- a moderate contribution of heredity to IQ
- therefore the heritability of IQ is between 40% - 70%
- obviously there’s not a single gene for intelligence
Adoption Studies
- extremely deprived environments → enriched environments
- IQ increases!
- IQ of adopted child → IQ of biological parents
Bottom line: IQ is influenced by genetic AND environmental factors
Environmental Influences
-
Amount of Schooling:
- studies of children with extra year of school - how our school system separates kids based on year of birth
- Summer Vacations: IQ drops before and after summer vacation
- Dropping Out: on average, have lower IQ scores as adults that stay in school
- Early Intervention Programs - Head Start
- seems to help initially but doesn’t last - the underlying situation (poverty, stress, malnutrition) still persists
- Expectancy effects of teacher’s part
- self-fulfilling prophecy/ prophecy of teacher
-
Poverty:
- poverty has a negative influence on IQ scores
- cumulative effect - longer child stays in poverty, the worse their IQ score will get
- lack of proper nutrition
- exposure to lead
- poverty has a negative influence on IQ scores
The Flynn Effect
On average, my IQ is 10-15 pts higher than my grandparents
Flynn Effect: average IQ of the population rises over time
Explanations for the Flynn Effect
- happening too fast to be genetic changes but certainly environmental
1. Better Nutrition- Flynn effect mostly occurs at lower tail of the bell curve
- it occurs mostly for people who were already lower on the bell curve (50 - 70 IQ range)
- less people scoring in that range than 50 years ago!
- it occurs mostly for people who were already lower on the bell curve (50 - 70 IQ range)
- on average, we are better nourished than our grandparents were
- Increased Test Sophistication
- we’re now more experienced at taking tests than people 50 years ago - making us better at taking/performing on tests
- Increased Complexity of the Modern World
- forced to process more/ higher information
- especially with social media
4. Changes at Home, School
- especially with social media
- families are smaller, therefore parents have more time to devote to kids, parents have access to resources, more time in school
- Flynn effect mostly occurs at lower tail of the bell curve
Group Differences in IQ: Sex Differences
- few or no average sex differences
-
Men: higher variability in overall IQ scores
- men are more susceptible to have intellectual disabilities
-
Women: score higher on verbal tasks, arithmetic calculation (childhood), emotional intelligence
- verbal ability influenced by level of estrogen?
-
Men: score higher on spatial ability tasks (mental rotation tasks), complicated mathematical reasoning tasks
- might be related to testosterone levels
** some of these differences only occur after childhood or adolescence **
Group Differences in IQ: Differences between Ethnic Groups
- US Statistics
- African & Hispanic Americans score lower than White Americans
- Asian Americans score higher than White Americans
- Canadian Statistics
- Canadian First Nations people scored on average 18pts lower than non-Indigenous people
Why do these differences exist?
-
Environmental Factors
- poverty, health-related variables, prejudice and discrimination, schooling
- Analogy: if you water and nurture a plant, it’s likely to grow more than the unwatered & under-nurtured plant
-
Measurement Factors
- taking tests in a second language
- cultural relevancy/ appropriateness of the test:
- Black Intelligence Test of Cultural Homogeneity
- even “culture-fair” tests may test aspects of culture that you don’t realize are present
- ex. cultures/ language/ groups differ in whether they words for shapes and spatial relations or quantities
- ex. written test-taking
- IQ differences among ethnic groups is narrowing
- variability within any given ethnic group is much higher compared to variability between ethnic groups
Within-Group Heritability
- extent to which a trait is heritable within a group
- ex. Asian Canadians; women
- ex. between men and women
