Intelligence

Intelligence

What is Intelligence?

  • Intelligence is a concept that is widely debated and defined.

  • Relative: It is defined in relation to the abilities of a comparison group, typically of the same age.

  • Hypothetically constructed: Intelligence is inferred from behavior rather than directly observed.

  • In all cultures, intelligence is generally considered the ability to:

    • Learn from experience.
    • Solve problems.
    • Apply knowledge to adapt to new situations (Fluid Intelligence).

  • In research, intelligence is often defined as what intelligence tests measure, which tends to focus on "school smarts."

Origins of Intelligence Tests

  • Intelligence tests aim to assess natural mental abilities and compare them among individuals.

  • The usefulness of these tests is debated, particularly regarding the influence of heredity versus environment.

  • The fundamental question remains: What do score differences truly signify?

  • The concept of intelligence testing originated with Plato's ideas and spread throughout Western societies.

Three Theories of Intelligence

  • Charles Spearman: Proposed the concept of general intelligence.

  • Howard Gardner: Proposed the theory of multiple intelligences (8 intelligences).

  • Robert Sternberg: Proposed the triarchic theory of multiple intelligences (3 intelligences).

General Intelligence (Spearman)

  • Charles Spearman (1863-1945):

    • Believed that a general factor underlies all of our mental abilities.
    • General intelligence (g) is linked to clusters of abilities that can be analyzed using factor analysis (FA).

  • Spearman’s Theory:

    • g factor: The ability to reason and solve problems; general intelligence.
    • s factor: The ability to excel in specific areas; specific intelligence.

  • Example: people who perform well on vocabulary exams also tend to do well on paragraph comprehension exams, indicating a cluster defining verbal intelligence.

  • Other factors include spatial ability and reasoning ability.

Factor Analysis

  • Factor analysis is a statistical procedure used to identify clusters or groups of related items (latent variables or factors) on a test.

  • Latent variables are underlying constructs that are not directly observable and cannot be measured by a single item.

  • Example: Marriage quality cannot be directly measured but can be assessed using observable variables like time spent together, environment, marital conflict, and attitudes.

  • Factor analysis helps researchers find similarities between variables used in experiments.

Cattell’s Theory of Intelligence

  • Fluid intelligence: The ability to solve new problems, use logic in new situations, and identify patterns. It tends to decrease with age.

  • Crystallized intelligence: The ability to use learned knowledge and experience. It tends to increase with age.

Theories of Intelligence - Gardner's Multiple Intelligences

  • In the mid-1980s, psychologists sought to broaden the definition of intelligence beyond academic smarts.

  • Howard Gardner (1983, 1999):

    • Believed that IQ scores measure only a limited range of human mental abilities.
    • Proposed that intelligence comes in multiple forms, with eight separate mental abilities referred to as multiple intelligences.

  • Different abilities allow us to cope with various environmental challenges.

  • Brain trauma may affect specific levels of intelligence.

Savant Syndrome

  • Individuals score low on intelligence tests but excel in abilities unrelated to general intelligence.

  • They possess remarkable, rare talents despite being mentally deficient in other areas.

  • Example: Kim Peek, the real Rain Man, had special reading abilities from a young age due to a lack of connections between his brain's hemispheres.

Gardner's Eight (Potentially Nine) Intelligences

  • Linguistic intelligence ("word smart")

  • Logical-mathematical intelligence ("number/reasoning smart")

  • Spatial intelligence ("picture smart")

  • Bodily-Kinesthetic intelligence ("body smart")

  • Musical intelligence ("music smart")

  • Interpersonal intelligence ("people smart")

  • Intrapersonal intelligence ("self smart")

  • Naturalist intelligence

  • Speculation about a ninth one: existential intelligence (ability to consider questions of life, death, and existence).

Robert Sternberg’s Triarchic Theory

  • Agrees with Gardner but proposes a triarchic theory with three intelligences:
    • Analytical Intelligence: Assessed by intelligence tests.
    • Creative Intelligence: Enables adaptation to novel situations and generation of novel ideas.
    • Practical Intelligence: Required for everyday tasks (e.g., street smarts).

Intelligence and Creativity

  • Creativity: The ability to produce ideas that are both novel and valuable.

  • Convergent thinking: Involves following logical steps to arrive at the "correct" answer.

  • Divergent thinking: Used to generate creative ideas by exploring many possible solutions; spontaneous, unorganized thought.

  • Creative people generate new, unexpected ideas through divergent thought, then organize them using convergent thought.

Convergent vs. Divergent Thinkers

  • Convergent Thinker:

    • Logical, objective, intellectual, realistic, planned, discriminative, structured, quantitative

  • Divergent Thinker:

    • Intuitive, subjective, emotional, imaginative, impulsive, holistic, free-wheeling, qualitative

  • Creativity correlates somewhat with intelligence, but a high IQ does not guarantee creativity.

  • Personality traits that promote divergent thinking are more important.

  • Sternberg identified five components of divergent thinkers and creativity:

    • Expertise: A well-developed knowledge base.
    • Imaginative Thinking: The ability to see things in novel ways.
    • Venturesome Personality: A personality that seeks new experiences.
    • Intrinsic Motivation: Motivation to be creative from within.
    • Creative Environment: A supportive environment allows creativity to flourish.

Emotional Intelligence

  • Introduced by Peter Salovey and John Mayer (1990).

  • Awareness of and ability to manage one’s own emotions to facilitate thinking.

  • Ability to be self-motivated and persistent.

  • Viewed as a powerful influence on success in life.

  • Empathy: The ability to understand what others feel.

  • Measures overall emotional intelligence and its four components:

    • Perceive emotion: Recognize emotions in faces, music, and stories.
    • Understand emotion: Predict emotions, how they change and blend.
    • Manage emotion: Express emotions in different situations.
    • Use emotion: Utilize emotions to adapt or be creative.

Criticism of Emotional Intelligence

  • Gardner and others question whether we stretch the idea of intelligence too far when applying it to our emotions.

Assessing Intelligence

  • Psychologists define intelligence testing as a method for assessing an individual’s mental aptitudes and comparing them with others using numerical scores.

Intelligence Quotient (IQ) Tests

  • IQ tests are used to identify differences in intelligence.

  • Geniuses: Fall at the extreme high end of the normal curve for intelligence.

  • Intellectually disabled: IQ scores fall well below the mean on the normal curve.

Alfred Binet and Modern Intelligence Testing

  • Alfred Binet (1857-1911) was a French psychologist who developed modern intelligence testing.

  • Binet & Theodore Simon were commissioned to study problems in the Paris school system.

  • They developed questions to predict children’s future progress in school.

Binet’s Focus on School Achievement

  • Aimed to identify students needing special help with the school curriculum.

  • This was necessitated by compulsory education for all French children.

  • Recognized huge differences in education levels, schooling, mental abilities, and learning abilities.

  • Developed an objective test to identify at-risk students.

Binet's Concepts: Dull vs. Bright Children & Mental Age

  • Mental Age – chronological age typical of a given level of performance.

  • Led to development of reasoning/problem-solving questions that might predict school achievement.

  • Binet feared labeling and only wanted to identify students needing special attention.

Binet-Simon Test Distinctions

  • Scores were interpreted at their current performance.

  • Used to identify students in need of help, not label or categorize them.

  • Emphasized that training and opportunity could affect intelligence.

  • Empirically constructed.

  • Scoring was done by calculating the mental age (MA) and the chronological age (CA).

    • MA = The average age at which normal individuals achieve a particular score
    • CA = The number of years since an individual's birth

  • SB5 is often used by educators to sort students for special educational programs.

Intelligence Testing Comes to America

  • The idea of IQ testing became popular in America for three reasons:

    • A huge increase in immigration
    • New laws requiring universal education
    • Military assessing new recruits for WWI

  • It created an inexpensive and objective way to separate those who could benefit from education or military leadership training from those who needed assistance.

Downsides of IQ Testing

  • Tests ended up reinforcing prevailing prejudices about race and gender.

  • Ignored environmental disadvantages which may limit the full development of peoples’ intellectual abilities.

IQ and William Stern

  • Created Intelligence Quotient (IQ)

  • Modern tests don’t compute IQ

  • IQ tests do not work well for adults

  • Average = 100

  • 2/3 of the population score between 85-115

  • Scores reflect innate mental ability, education, & familiarity with culture assumed by test

Lewis Terman and Eugenics

  • Terman adapted Binet’s test for American school children and named it the Stanford-Binet Test IQ Test.

  • Terman believed in eugenics:

    • Eugenics: a social movement aimed at improving the human species through selective breeding…promoted higher reproduction rates of people with ‘superior’ traits and aimed to reduce reproduction rates of people with ‘inferior’ traits.

Lewis M. Terman’s Study:

  • Shattered myth of weakling genius.

  • Early findings showed that the gifted, also called “termites,” were socially well adjusted, skilled leaders.

  • Above average in height, weight, and physical attractiveness.

  • People with IQ of 180 and above found to have some social and behavioral adjustment problems.

Intelligence Test Scores and the Normal Curve

  • Scores are typically represented by the normal curve.

  • Percentages under each section of the normal curve represent the percentage of scores falling within that section for each standard deviation from the mean.

David Wechsler and Intelligence Scales

  • Wechsler developed:
    • Wechsler Adult Intelligence Scale (WAIS)
    • Later developed the Wechsler Intelligence Scale for Children (WISC), an intelligence test for school-aged children.

Wechsler Scales

  • Designed for specific age groups

  • The Wechsler Adult Intelligence Scale (WAIS-IV)

  • Wechsler Intelligence Scale for Children (WISC-IV)

  • Wechsler Preschool and Primary Scale of Intelligence (WPPSI-IV)

  • Yield a verbal and a performance score, as well as an overall score of intelligence.

  • 11 other aspects related to intelligence that are designed to assess clinical and educational problems.

Principles of Test Construction

  • For a psychological test to be acceptable, it must be:
    • Standardized
    • Reliable
    • Valid

Standardization

  • The process of giving the test to a large group of people representative of the actual population the test is designed for:

  • Establishment of consistent and standard methods of test administration.

  • Use of comparison group whose scores are used to compare individual test results

  • Norms: scores from a standardized group of people distributed mostly around the mean on the normal curve

Normal Curve in Standardized Tests

  • Standardized tests establish a normal distribution of scores on a tested population in a bell-shaped pattern called the normal curve.

Reliability in Psychological Testing

  • The tendency of a test to produce the same scores again and again each time it is given to the same people.

  • To establish reliability, researchers establish different procedures:

    • Split-half Reliability: Dividing the test into two equal halves and assessing how consistent the scores are.
    • Test-Retest Reliability: Using the same test on two occasions to measure consistency.

Validity in Psychological Testing

  • Reliability of a test does not ensure validity.

  • Validity of a test refers to what the test is supposed to measure or predict.

  • Content Validity: Refers to the extent a test measures a particular behavior or trait.

  • Predictive Validity: Refers to the function of a test in predicting a particular behavior or trait.

Extremes of Intelligence

  • A valid intelligence test divides two groups of people into two extremes:

    • The mentally retarded (IQ < 70)
    • Individuals with high intelligence (IQ > 130).

  • These two groups are significantly different.

Giftedness and High Intelligence

  • 2% of the population falling on the upper end of the normal curve

  • IQ of 130 or above

  • Geniuses: IQ falls above 140 to 145

  • Joan Freeman’s views:

    • Differing life conditions for the gifted serve as a major factor in their success, adjustment, and well-being
    • Gifted children pushed to achieve at younger ages grow up as unhappy adults

  • Contrary to popular belief, people with high intelligence test scores tend to:

    • Be Healthy
    • Be Well-adjusted
    • Be Unusually successful academically

Intellectual Disability (Intellectual Developmental Disorder)

  • Condition in which a person’s behavioral and cognitive skills exist at an earlier developmental stage than the skills of others who are the same chronological age.

  • IQ score falls below 70 on a test with a mean of 100 and standard deviation of 15

  • Adaptive behavior is severely below standards.

  • Limitation begins in the developmental period

  • Occurs in about 1% of the population

Mental Retardation & Current Approach

  • Required constant supervision a few decades ago.

  • Currently, with a supportive family environment and special education, they can now care for themselves.

Diagnosis for Intellectual Disability

  • DSM-5 diagnosis of intellectual disability functions across three domains:

    • Conceptual: memory, reasoning, language, reading, writing, math, and other academic skills.
    • Social: empathy, social judgment, interpersonal communication, and other skills that impact the ability to make and maintain friendships.
    • Practical: self-management skills that affect personal care, job responsibilities, school, money management, and other areas

  • The diagnosis removes the specific age criteria

Causes of Low IQ

  • Unhealthy living conditions: lead poisoning.

  • Deficits: malnutrition, inadequate access to health care, lack of mental stimulation, etc.

  • Biological causes of intellectual disability:

    • Down syndrome
    • Fetal alcohol syndrome: a condition resulting from exposing a developing embryo to alcohol
    • Fragile X syndrome: defective gene on the X chromosome of the 23rd pair leading to a deficiency in a protein needed for brain development

Additional Causes of Low IQ

  • Other causes:

    • Lack of oxygen at birth
    • Damage to the fetus in the womb from disease, infections, or drug use by the mother
    • Diseases and accidents during childhood

  • Individuals with an intellectual disability are just as responsive to love and affection as anyone else

Usefulness of IQ Tests

  • IQ tests valid for predicting academic success and job performance

  • Recent research suggests skills in self-regulation or levels of motivation may impact IQ measures.

  • Plays an important role in neuropsychology where neuropsychologists use intelligence testing in diagnosis

Flynn Effect

  • In the past 60 years, intelligence scores have risen steadily by an average of 27 points.

  • This phenomenon is known as the Flynn effect.

  • Due to the Flynn effect, IQ test scoring must occasionally be reworked in order to “reset” the average score to 100.

  • If you took an IQ test from when your grandparents were children, you would likely score higher than on a modern IQ test.

Observed Effects

  • Substantial and long-sustained increase in both fluid and crystallized intelligence test scores.

  • Measured in many parts of the world from roughly 1930 to the present day.

Genetic Influences on Intelligence

  • Studies of twins, family members, and adopted children together support the idea that there is a significant genetic contribution to intelligence.

Adoption Studies and Verbal Ability

  • Adopted children show a marginal correlation in verbal ability to their adopted parents.

Heritability of Intelligence

  • The variation in intelligence test scores is attributable to genetics.

  • We credit heredity with 50% of the variation in intelligence.

  • It pertains only to why people differ from one another, not to the individual.

Environmental Influences on Intelligence

  • Studies of twins and adopted children also show the following:
    • Fraternal twins raised together tend to show similarity in intelligence scores.
    • Identical twins raised apart show slightly less similarity in their intelligence scores.

Early Intervention Effects

  • Early neglect from caregivers leads children to develop a lack of:

    • personal control over the environment

  • it impoverishes their intelligence.

  • Romanian orphans with minimal human interaction are delayed in their development.

Schooling Effects on Intelligence

  • Schooling is an experience that pays dividends, which is reflected in intelligence scores.

  • Increased schooling correlates with higher intelligence scores.

  • To increase readiness for schoolwork, projects like Head Start facilitate leaning.

Ethnic Similarities and Differences in Intelligence

  • Racial groups differ in their average intelligence scores.

  • High-scoring people (and groups) are more likely to attain high levels of education and income.

Racial (Group) Differences

  • White-Americans: Average IQ = 100

  • Black-Americans: Average IQ = 85

  • White Americans score higher in average intelligence than black Americans (Avery and others, 1994).

  • European New Zealanders score higher than native New Zealanders (Braden, 1994).

Environmental Effects on Group Differences

  • Differences in intelligence among these groups are largely environmental.

  • If one environment is more fertile, it develops more abilities than the other.

Reasons Why Environment Affects Intelligence

  • Races are remarkably alike genetically.

  • Race is a social category.

  • Asian students outperform North American students on math achievement and aptitude tests.

  • Today’s better prepared populations would outperform populations of the 1930s on intelligence tests.

  • White and black infants tend to score equally well on tests predicting future intelligence.

  • Different ethnic groups have experienced periods of remarkable achievement in different eras.

Stereotype Threat

  • A condition in which being made aware of a negative performance stereotype interferes with the performance of someone that considers himself or herself part of that group.

Gender Similarities and Differences in Intelligence

  • Girls are better spellers

  • Girls are verbally fluent and have large vocabularies

  • Girls are better at locating objects

  • Girls are more sensitive to touch, taste, and color

  • Boys outnumber girls in counts of underachievement

  • Boys outperform girls at math problem-solving, but underperform at math computation

  • Women detect emotions more easily than men do

  • There are seven ways in which males and females differ in various abilities.

Question of Bias in Aptitude Tests

  • Aptitude tests are necessarily biased in the sense that they are sensitive to performance differences caused by cultural differences.

  • However, aptitude tests are not biased in the sense that they accurately predict the performance of one group over the other.

Cultural Bias & IQ Tests

  • Intelligence tests free of cultural bias are difficult to design

  • One attempt was to eliminate language and design tests with demonstrations and pictures.

  • A “culture-fair” test requires the use of nonverbal abilities like object rotation

    • More culturally fair
    • Does not measure other important mental abilities like verbal knowledge

Artificial Intelligence

  • Designing and programming computer systems

  • to do intelligent things

  • to simulate human thought processes through:

    • intuitive reasoning
    • learning
    • understanding language

Practical Applications and Computer Neural Networks

  • Includes practical applications

  • chess playing

  • industrial robots

  • expert systems

  • Efforts to model human thinking are inspired by our current understanding of how the brain works.

  • Computer Neural Networks:

    • Computer circuits that mimic the brain’s interconnected neural cells.

    • Performing tasks

    • learning to recognize visual patterns

    • learning to recognize smells