Chapter 26 - Intelligence

Leilani Muir

• at 10 years old - placed in Provincial Training School for Mental Defectives

• at 13 years old - completed IQ test and scored 64 (average score should be 100)

  • was diagnosed as a Mental Defective Moron

• at 14 years old - sterilized without her consent

  • due to Alberta’s 1928 Sexual Sterilization Act

Leilani Muir as an adult and what this shows

she later redid the IQ test and scored 89, which is closer to the average

• tells that it is important to measure things properly, especially intelligence

  • because due to the sterilization, she cannot have kids now

Sir Francis Galton

• believed that people who are better at taking in information would be overall smarter

• created 17 sensory tests (similar to absolute thresholds)

• he used Anthropometrics

• but his methods of testing were completely flawed

Anthropometrics

methods of measuring physical and mental variation in humans

• ex. ability to judge different colours, ability of memory

Alfred Binet

french researcher who assumed that intelligence was associated with more complex abilities like attention, memory, and comprehension

Intelligence

ability to think, understand, reason, and adapt to or overcome obstacles

Binet-Simon Test

Binet and Theodore Simon

• test that identifies students who needed specialized education

  • used 30 tasks including defining words, making sentences out of specific words, and reproducing drawings

Mental Age

average intellectual ability score for children of a specific age

• you could be 10 years old but score intellectually lower than the average, meaning your mental age could be younger

Lewis Terman of Stanford

calculated norms for each chronological age

Stanford-Binet test

an intelligence test intended to measure innate levels of intelligence

Terman vs. Binet

Binet - believed that intelligence could change over time

Terman - believed that intelligence was an innate, unchangeable characteristic

Intelligence Quotient (IQ)

• used to rank a person’s intellectual ability against others

IQ score = (mental age (MA) / chronological age (CA) ) x 100

• mental age - based on how intellectually you perform

• chronological age - how old you actually are

a child of 8 performed like the average 10 year old. What is his mental age and IQ?

mental age would be 10

IQ = (10 / 8) x 100 = 125

problems with IQ score

a 40 year old with mental age of a 30 year old doesn’t mean they’re dumb

• there needed to be another way to measure IQ of adults

  • so they made deviation IQs

Deviation IQs

determining intelligence based on how an individual’s scores deviate from the average of that age group

• how your intelligence differs (deviates) from the average intelligence of people your age

average and standard deviation of IQ

average IQ - 100

standard deviation - 15

2 main subdivisions of the Wechsler Adult Intelligence Scale (WAIS)

• General Ability Index (GAI) - examines comprehension and reasoning without examining processing speed

• Cognitive Proficiency Index (CPI) - working memory and processing speed tasks

  • abilities allow more cognitive resources to be directed toward reasoning

General Ability Index task examples

• Verbal Comprehension Index

  • similarities, vocabulary, info

• Perceptual Reasoning INdex

  • block design, matrix reasoning, visual puzzles

Cognitive Proficiency Index task examples

• Working memory index

  • Digit span, arithmetic

• Perceptual Speed index

  • symbol search, coding

Symbol-Digit Modalities Test

• example of a Coding task

• sensitive to TBI and age-related deficits

what has studies found about average IQ of university students

average IQ of population is 100

university students IQ found to be nearly the same as average IQ of population

problems with WAIS

• there are some cultural biases in the WAIS since it caters more towards North America

• difficult when introduced to other countries, languages, and cultures

  • can end up testing language ability rather than cognitive ability

Raven’s Progressive Matrices

intelligence test that is based on pictures (not words) making it relatively unaffected by language or cultural background

Galton’s Intelligence tests and what they show

Galton was from a family of successful people like Charles Darwin

• his intelligence tests were developed in Victorian England

  • British Empire had much control of parts of the world

• because of his views and his environment, he blindly assumed that inherent intellectual ability ran in families which was due to “good breeding”

American Tests and racism in society

American tests were developed when racial segregation was still common

• biased towards people who already went to school (Caucasians) since they were able to, as opposed to the new immigrants

• Some ethnic groups were directed towards manual labour instead of going to school, due to these unfair tests classifying them as dumb

• In the military, there was ethnic difference where some ethnic groups were sent in as cannon fodder

Eugenics

encouraging breeding between people with particular traits and discouraging breeding between those without these traits (ex. people with low IQs)

what did early Eugenists believe

they genuinely thought they were going to make society better

• however, forced sterilization meant that weaker characteristics would be “bred out” of the population

• and some were simply racist

"The Bell Curve”

by Herrstein and Murray

• book that stated society consists of the cognitive elite and the less intelligent

  • lower IQ scores were generally found in Indigenous, Black, and Latin American descent

    • and were thus treated more poorly

  • a healthy society would be a meritocracy

problems with Racial Superiority interpretation

even unbiased tests produce race differences

• due to familiarity with standardized tests, motivation to do well on tests, and discomfort with formal testing environments

stereotype threat

when negative stereotypes about a group cause group members to underperform on ability tests

• influences sex differences, ethnic minorities, the elderly, and the poor

• ex. a female may become self conscious to speak in front of a group of men about driving, because there is a stereotype that women are bad drivers

Stereotype threat and how it affects test results

• increases arousal

  • (fight or flight response)

  • because individuals are concerned that a poor performance may reflect poorly on their group

• increases self-focused thoughts

  • can develop:

  • anxiety → worse performance

  • disidentification → reduced motivation

• increases inhibition

  • the tendency for people to try to inhibit negative thoughts they have

  • reduces the cognitive resources available for the test

Entity Theory

the belief that intelligence is a fixed characteristic and relatively difficult to change

incremental theory

the belief that intelligence can be shaped by experiences, practice, and effort

Entity vs. Incremental theory effects

• kids who believed in entity theory were more likely to give up than kids who believed in incremental theory

• students who were taught incremental theory had improved grades over time

Entity vs. Incremental theory and its effects on culture

• asians are more likely to believe in incremental theory

• North americans are more likely to believe in the entity theory

  • parents had lower academic standards for kids compared to other cultures

  • children valued education less

Factor analysis

created by Charles Spearman

statistical technique that examines correlations between variables to find clusters of related variables or “factors”

• scores on tests of vocabulary, reading comprehension, and verbal reasoning correlate highly together

  • forms “language ability” factor

• someone who is good at one subject is probably good at other subjecrs

general intelligence factor g

performance in tasks of mental ability was dependent on a general intelligence factor, g

• assumes intelligence is a basic cognitive trait that is made up of the ability to learn, reason, and solve problems, regardless of their nature

• correlates with perceptual decision-making speed and efficiency of nerve conduction

effects of g

having higher levels of g means

• less likely to be poor

• less likely to get divorced

• less likely to be thrown in jail

problems with g

g does not solely correlate to having good grades, income levels, etc.

• there are are other factors

Louis Thurstone

use factor analysis and found that instead of a single g, there were actually 7 different clusters of abilities that people have

• word fluency

• verbal comprehension

• numeric abilities

• spatial visualization

• memory

• perceptual speed

• reasoning

How did Spearman alter g

• noted that the 7 different clusters that Thurstone found were actually all correlated with each other

  • g is the correlation between these clusters of abilities

• suggested that along with the general influence of g, all tasks require specific abilities, s

• intelligence consists of a general ability (g) and an unknown number of specific abilities (s)

Hierarchical Model

specific skills (s) are nested within primary mental abilities (g)

• this is the accepted model of intelligence today

ex. primary mental abilities (g) - being verbal or math smart

specific skills - being good at public speaking vs. writing good essays

Raymond Catell

believed g had 2 componenets

• fluid intelligence (Gf)

• Crystallized intelligence (Gc)

fluid intelligence (Gf)

type of intelligence used in learning new info and solving new problems not based on knowledge that you already know

• easier for younger people as opposed to older people, whose cognitive capacity to learn reduce

• ex. Raven’s progressive matrices

Crystallized intelligence (Gc)

type of intelligence that includes past learning and experience

• vocabulary and general knowledge

fluid vs. crystallized intelligence

• fluid intelligence reaches its peak before age 20, remains steady, and then decreases

• crystallized intelligence continues to increase with age as long as the person is active and alert

Howard Gardener

came up with and believed that there were Multiple Intelligences

Multiple intelligences and problems with this theory

model of claiming that there are at least nine different forms of intelligence that are independent of each other

problem: this theory is unfalsifiable

• you can always think up a new type of intelligence to account for the data

• there was also no way to test this theory

Savant

an individual with low mental capacity in most domains but extraordinary abilities in other specific areas

• art

• calendar calculating

• mathermatics

• mechanical skills

• spatial skills (map making, distance measuring)

savants are typically males (6:1 ratio male to female savants known)

Prodigious savants and Sephen wiltshire

have spectacular abilities in one area

• there are < 100 prodigious savants know

• steven wiltshire is an example of a savant

  • could draw detailed pictures of cities after twenty minute helicopter rides

Emotional intelligence (EQ)

• ability to:

  • identify your own and other people’s emotions accurately

  • express your emotions clearly

  • regulate emotions in yourself and others

  • delay gratification

• biologically based

  • frontal lobe damage impairs EQ

IQ in males vs. females

same average IQ score between males and females

• but greater variability in male scores

• more men who are geniuses

• more men with substantial intellectual challenges

overlapping curves of male and female abilities

researchers found

• small differences between males and females

• larger differences within male groups and female groups

Grey Anatomy of male vs. female brains

• women have 10% more white matter

• frontal cortex is bulkier in women (more neurons for language-processing areas in temporal lobe)

• parietal cortex (spatial skills/attention) and amygdala (emotional reactions) is large in men

but these are are very very little differences

Einstein’s brain

average human brain weighs between 1,300-1,400g

• einstein’s brain was 1230g

• shows that a larger brain doesn’t mean a more powerful brain

Brain Size and intelligence

• humans have more cortical folds (convolutions) than other species

• higher WAIS scores = more convolutions

• this could explain about 25% of variability in WAIS scores

P-FIT Model of Intelligence

• Fronto-Parietal Integration Theory

• suggests that most of the areas related to individual differences in intelligence are in the frontal and parietal lobes of the brain

Intelligence and Heredity (in twin studies)

• twin studies showed that monozygotic twins (raised together or apart) have more similar intelligence than the intelligence of other sibling relationships (raised together or apart)

• the more genetic material you have in common with a person, the more likely you are to have similar IQ scores

Gene knockout studies

involve removing a specific gene and testing the effects of removing the gene by comparing animals without the gene to those that have it

transgenic animal studies

• inserting genetic material in mouse chromosomes

Doogie Mice

have an altered version of the NR2B gene, which is related to learning and memory

environment (socioeconomic status) and IQ

• IQ scores would probably go up or down if every child got the same early environment, but some differences would remain

• enriched environments with a lot of cognitive stimulations improve intellience

• poor environments are correlated with lower IQ scores

  • being more poor = more stress

• this shows there is power of socioeconomic status

Birth Order Effects

• the IQs of first-born children are, on average, about 3 points higher than second-born children and 4 points higher than third-born children

Nootropic substances

• believed to beneficially affect intelligence

• ex. Ritalin boosts cognitive performance by blocking reuptake of norepinephrine and dopamine

• ex. Adderall

Meditation and intelligence

• increases thickness and density of white-matter pathways connecting the anterior cingulate gyrus to other brain regions

  • related to attentional and emotional control

• can slow down rate of cognitive decline and the loss of grey matter in the brain normally associated with aging

Norm

range of scores based on a sample of the population, used to base the score that an individual will get on a test