lecture 2 - history of intelligence in psychology Flashcards
where is started
The modern investigation of intelligence began at the end of the 19th Century through two men: Francis Galton and Alfred Binet.
galton - how mental and physical features can be inherited through generations
binet - generated intelligence test for special needs children - test doesnt work on American children
lewis terman
Following Galton and Binet, the USA began making its own investigation into intelligence, beginning with Lewis Terman of Stanford University. tested over 1000 children age 4-14.
beginning of standardised testing - large sample many ages to produced bell curve
problem - cultural measures in how we measure IQ
William stern
One of the major advances towards standardized testing was made in 1912 by German Psychologist William Stern.
He developed the idea of Intelligence Quotient (IQ), where each person would get one figure that would indicate a general level of intelligence
created norms eg from 7yr old
terman adopted the method
calculate by
mental age / chronological age x 100 to get score
100 is average
compare kids of different ages on diff IQ tests
what about adults
Robert Yerkes, along with a team that included Lewis Terman, developed two intelligence tests for adults.
The Army Alpha test was designed for literate groups. It comprised of 8 subsets.
The Army Beta test was designed for illiterates. It comprised of 7 subsets.
both tests completed in certain amount of time - researcher does not need to be present
scores in letters
raised topic of intelligence in society and developing more IQ tests - so 1919 national IQ test
American army wanted to assign different soldiers to different jobs - previous IQ tests not appropriate
on 1.57 m soldiers - did not contribute to war effort - maybe IQ tests are not that helpful?
some controversy
The heritability of intelligence.
Race and sex differences in intelligence.
is nature or nurture cause of intelligence?
heritability
Galton coined term nature vs nurture
Galton found that the number of eminent relatives of an eminent person was greater for first degree than second degree relatives, and greater for second degree than third degree relatives. - he studied obituaries - degree of relationship between relatives
he set the rationale for twin and adoption studies
the more biologically close people are the more close in intelligence - used status in society as a measure which is a problem with this method
heritability of intelligence estimates by Bouchard and McGee 1981, Eysenck, 1979, 2019; Ridley, 1999)
supports galton and suggests good heritability of IQ, genetics and environment both play a role
identical twins reared together = 86%
identical twins reared apart = 76%
fraternal twins reared together = 55%
biological siblings reared together = 47%
parents and children living together = 40%
parents and children living apart = 31%
biological siblings reared apart = 24%
cousins = 15%
The environment
(Bouchard & Segal, 1985;
Neisser et al., 1996) - 21 environmental factors are linked to intelligence
Neisse et al = task force lead, identified 4 areas on how the environment can impact intelligence
Biological variables (Erikson et al., 2012; Herrmann et al., 2008; Nyaradi et al.,
2013; McMichael et al., 1994). - like prenatal factors like smoking and nutrition
Family (Baker & Daniels, 1990; Belmont & Marolla, 1973; Dumitrashku, 1996;
Gottfredson, 1986). - studied by comparing siblings raised in different environments, socio-economic status of family, birth order
School and education (Ceci & Williams, 1997; Ritchie & Tucker-Drob, 2018). - going to school increase IQ, high IQ improves performance at school. relationship between school and IQ. each yr missed at school us = -6 IQ points
Culture (Sternberg & Grigorenko, 2004) - different ideas on what intelligence is in different cultures
Bouchard and loehlin (2001)
created a framework that combines the genetic and environmental influences on behavior.
conducted a review of behavioral genetics research, particularly focusing on the heritability of personality traits and intelligence. Their work emphasized findings from twin and adoption studies, which showed that:
Genetic factors play a significant role in shaping personality and cognitive abilities, with heritability estimates for major personality traits typically around 40–50%.
Shared environment (e.g., growing up in the same family) has less influence than previously thought, especially on personality.
Non-shared environment (experiences unique to each individual) and genetic influences are more significant in explaining individual differences.
Their research supported the idea that both nature and nurture contribute to psychological traits, but genetics may have a larger role than traditionally assumed, particularly in adulthood.
In summary, Bouchard and Loehlin (2001) helped solidify the view that genetic influence on personality and intelligence is substantial, while shared environmental influences are more limited.
galton - eugenics
peoples views on if intelligence is nature or nurture have severely impacted the course of history.
galton was an advocate of eugenics - he was an advocate of intelligent people reproducing and less intelligent not
race
Herrnstein and Murray (1994) published a book called ‘The bell curve: intelligence and class structure in American life’.
At heart, the book is an analysis of IQ test scores throughout the USA.
However, its content caused uproar.
its pre 1980 - 50yrs
themes of -
The cognitive elite. – people who are smart are more efficient at jobs
Socio-economic variables eg poverty and unemployment and IQ score. - suggested low IQ causes these things = low welfare and criminality
The relationship between intelligence and race. - problematic - thought intelligence passed through genes and fixed so can’t improve it - white American score 15 points more than black Americans, asian Americans 5 points more than white Americans
their new bell curve
diagram in notes
one problem is not the data but the interpretation and conclusions drawn from it
conc = need to improve opportunities for people - not actual conclusion made
Implications and solutions
National IQ is getting lower. - due to certain social factors
Intervention won’t work. - as ‘tried’ so no point inc opportunities
Spend more resource supporting high IQ people.
Critique
- The assumptions
- The stats
- The dark side
scientific community saw analysis was flawed
the assumptions
issue - a no represents IQ - but there may be different types of IQ and cultural influences
Gould (1995) ripped apart the 6 premises of the book to attack the arguments made for policy in the USA.
In other words, the premises on which the book is founded are questionable, making the authors social recommendations insecure.
the stats
most were a correlation so causation can’t be informed, they are associated - don’t know causal factor
Kamin (1995) levelled three criticisms in this regard.
Statistical knowhow.
Validity of measures.
Research used to build arguments.
The dark side
Many felt that the book was raising the issue of eugenics. Let me give you a little history lesson about why this was a worry.
Critics, such as Gould (1995), suggested that the book, without explicitly pointing to eugenics, inferred thoughts and practices that were consistent with it.
And the book isn’t helped by the fact that much of its evidence is based on that of Richard Lynn, who has been one of the most outspoken advocates of eugenics.
Interesting note: is there even such a thing as race, from a genetic point of view? (Collins et al., 2003; Duello et al., 2021).
Sex differences
Terman (1916) found that girls scored slightly higher than boys when he originally tested the Stanford-Binet. - but nothing conclusive
Court (1983) wrote the first systematic review on differences in intelligence across sex and found no differences.
Jenson (1998), MacKintosh (1998) and Anderson (2004) substantiated these claims with their own analyses.
however
Richard Lynn wrote a letter to ‘The Psychologist’ magazine suggesting that his findings show this to be wrong.
Lynn and Irwing (2004) conducted a meta-analysis and found that men tended to score 3-5 points higher than women on Raven’s matrices.
further research
In a seminal paper, Maccoby and Jacklin (1974) concluded that men score better on measures of spatial ability than women. - able to mentally rotate and manipulate objects - if good, good at navigating environments etc
A series of meta-analyses (Feingold, 1988; Hedges & Nowell, 1995; Linn & Peterson, 1985; Hyde & Linn, 1988; Voyer, Voyer & Brydon, 1995) revealed further differences in some specific abilities, and especially spatial abilities.
But why?
Brain size (Lynn, 1994). - mens brains are 10% bigger, believed to be related to intelligence
Evolution (Jones, Braithwaite & Healy, 2003). - left parietal lobe and men good at foraging passed down genes - better spatial abilities , women have better verbal ability than men
Brain functioning (Haier et al., 2005).
Testosterone (Choi & Silverman, 2002). - higher have better spatial ability
Stereotypes (Halpern & LaMay, 2000; Stoet & Geary, 2012). - stereotype threat - makes people perform badly eg women, boys encourage to take particular subjects - better spatial abilities
example essay qus
- Critically discuss the proposition that sex differences exist in intelligence.
Are intelligence tests a good way of measuring intelligence?
Boake (2002) - “From the Binet-Simon to the Wechsler-Bellevue: Tracing the History of Intelligence Testing”: - Background & Purpose
- The paper reviews the history of intelligence testing, focusing on the development of David Wechsler’s intelligence scales.
It traces the origins of the subtests in the 1939 Wechsler-Bellevue Intelligence Scale, which came from tests developed between the 1880s and World War I.
Boake (2002) - early mental testing
- Pre-Binet Intelligence Measures
○ Francis Galton (1884) introduced anthropometric measures (reaction times, sensory abilities) as a way to study intelligence.
○ James McKeen Cattell (1890) coined the term “mental test” and adapted Galton’s methods to test college students.
○ Édouard Séguin (mid-1800s) developed form boards for assessing cognitive abilities in children with intellectual disabilities.- Binet-Simon Intelligence Scale (1905, 1908)
○ Developed by Alfred Binet and Théodore Simon to assess schoolchildren’s intellectual abilities.
○ Introduced mental age as a measure of intelligence.
○ Focused on verbal tasks, but critics argued it was too language-dependent. - Revisions & U.S. Adaptations
○ Lewis Terman (Stanford-Binet, 1916) introduced the IQ score (mental age ÷ chronological age × 100).
Robert Yerkes (1915) created the Yerkes-Bridges Point Scale, organizing intelligence tasks into subtests instead of age levels.
- Binet-Simon Intelligence Scale (1905, 1908)
Boake (2002) - Performance-Based Intelligence Testing
- Non-Verbal Tests for Immigrants & Illiterate Individuals
○ Ellis Island Tests (1910s): Performance-based tests (puzzles, form boards) were used to assess non-English-speaking immigrants.
○ Pintner-Paterson Performance Scale (1917): Developed for deaf children to measure intelligence without relying on language.- Army Intelligence Testing (World War I, 1917-1919)
○ Army Alpha Test: Verbal, written test for literate recruits.
○ Army Beta Test: Non-verbal test for illiterate or non-English-speaking recruits.
○ Individual Examination: A more detailed one-on-one assessment for those who failed Alpha/Beta.
Many of these tests later influenced Wechsler’s subtest selection.
- Army Intelligence Testing (World War I, 1917-1919)
Boake (2002) - Wechsler-Bellevue Intelligence Scale (1939)
- David Wechsler’s Background
○ Worked with intelligence tests during WWI as an Army psychological examiner.
○ Became chief psychologist at Bellevue Psychiatric Hospital (1932).
○ Aimed to create a test for adults that combined both verbal and non-verbal measures.- Key Innovations of the Wechsler-Bellevue Scale
○ Deviation IQ: Instead of using mental age, Wechsler introduced standardized scores based on a normal distribution (mean = 100, SD = 15).
○ Verbal & Performance Scales: Unlike earlier tests that focused on verbal tasks, Wechsler balanced verbal and non-verbal (performance) subtests.
○ Subtests Borrowed from Earlier Tests:
§ Verbal Subtests: Derived from the Binet-Simon, Yerkes-Bridges, and Army Alpha tests.
§ Performance Subtests: Inspired by Ellis Island tests, Army Beta, Pintner-Paterson Scale, and Kohs Block Design.
Clinical Utility: Designed for psychiatric patients and individuals with brain injuries, making it more applicable beyond education.
- Key Innovations of the Wechsler-Bellevue Scale
Boake (2002) - Legacy & Impact
- Revisions & Adaptations
○ Wechsler Intelligence Scale for Children (WISC, 1949) adapted the adult test for younger populations.
○ Wechsler Adult Intelligence Scale (WAIS, 1955, 1981, 1997, WAIS-III, WAIS-IV) refined the test over time.
○ Wechsler Memory Scale (WMS, 1945) was developed separately to assess memory function.- Why Has the Wechsler Model Persisted?
○ Despite advancements in psychology, the core structure of the Wechsler test remains largely unchanged.
○ Factor analysis has confirmed the validity of the Verbal vs. Performance IQ distinction.
○ The test’s wide clinical and educational applications have solidified its status as the dominant individual intelligence test.
- Why Has the Wechsler Model Persisted?
Conclusions
* The Wechsler-Bellevue Scale was not a completely new invention—it was a synthesis of intelligence tests from the Binet-Simon era, WWI military tests, and performance-based assessments.
* Wechsler’s biggest contributions were:
1. The deviation IQ model (instead of mental age).
2. Integrating verbal and performance measures.
3. A focus on adult intelligence assessment.
The slow pace of change in intelligence testing suggests that Wechsler’s model is still scientifically and practically robust, despite ongoing debates about intelligence measurement
“Contemporary Theories of Intelligence” by James C. Kaufman, Scott Barry Kaufman, and Jonathan A. Plucker, published in The Oxford Handbook of Cognitive Psychology (2013): overview
- The chapter examines modern theories of intelligence, moving beyond traditional IQ-based models.
- It highlights theories that shape intelligence testing and measurement (e.g., CHC theory, PASS model).
- It also discusses alternative perspectives that challenge or expand the traditional view, such as Multiple Intelligences and Emotional Intelligence.
Neuroscientific and cognitive models (e.g., Parieto-Frontal Integration Theory, Dual-Process Theory) are also explored.
“Contemporary Theories of Intelligence” by James C. Kaufman, Scott Barry Kaufman, and Jonathan A. Plucker, published in The Oxford Handbook of Cognitive Psychology (2013): Key Theories of Intelligence
- Cattell-Horn-Carroll (CHC) Theory
- A widely used model in modern intelligence tests.
- Combines two earlier theories:
○ Fluid Intelligence (Gf): Problem-solving, reasoning, independent of acquired knowledge.
○ Crystallized Intelligence (Gc): Knowledge gained from experience and education. - Expanded to 10 broad cognitive abilities, including visual processing, short-term memory, and processing speed.
- PASS Model (Planning, Attention, Simultaneous, Successive)
- Based on Luria’s neuropsychological model.
- Suggests intelligence is not just about g-factor but involves:
○ Planning (strategic thinking).
○ Attention (focus and control).
○ Simultaneous Processing (integrating multiple pieces of information).
○ Successive Processing (step-by-step learning).
- Multiple Intelligences (Howard Gardner)
- Challenges traditional IQ models, arguing for eight distinct intelligences:
- Linguistic
- Logical-mathematical
- Spatial
- Musical
- Bodily-kinesthetic
- Interpersonal
- Intrapersonal
- Naturalistic
- Criticized for lack of strong empirical evidence and overlap with existing abilities.
- Challenges traditional IQ models, arguing for eight distinct intelligences:
- Successful Intelligence (Robert Sternberg)
- Intelligence is not just about IQ but about adapting to life challenges.
- Three key components:
○ Analytical Intelligence (problem-solving, logical reasoning).
○ Creative Intelligence (innovation, generating new ideas).
○ Practical Intelligence (street smarts, applying knowledge in real life).
- Emotional Intelligence (EI)
- The ability to understand, manage, and use emotions effectively.
- Mayer-Salovey-Caruso model:
○ Perceiving emotions (recognizing feelings in self and others).
○ Using emotions (enhancing thinking and decision-making).
○ Understanding emotions (knowing causes and consequences of emotions).
○ Managing emotions (regulating feelings in oneself and others).
Mixed models of EI (e.g., Goleman’s) include personality traits, making it harder to measure reliably.
“Contemporary Theories of Intelligence” by James C. Kaufman, Scott Barry Kaufman, and Jonathan A. Plucker, published in The Oxford Handbook of Cognitive Psychology (2013): Neuroscientific & Cognitive Models of Intelligence
- Parieto-Frontal Integration Theory (P-FIT)
- Intelligence is not localized in the brain but depends on a network of regions, primarily in the parietal and frontal lobes.
- Information flows from sensory areas to problem-solving centers.
- More efficient brain connectivity is linked to higher intelligence.
- Minimal Cognitive Architecture (MCA)
- Intelligence emerges from two processing routes:
- Thoughtful problem-solving (dependent on processing speed).
- Automatic, domain-specific processing (e.g., spatial awareness, language).
- Suggests that intelligence differences arise from variations in brain architecture.
- Intelligence emerges from two processing routes:
- Dual-Process Theory
- Intelligence is shaped by two cognitive systems:
- Goal-directed cognition (effortful thinking, problem-solving, metacognition).
- Spontaneous cognition (intuition, creativity, gut feelings).
Suggests that intelligent behavior arises from a balance between the two systems.
- Intelligence is shaped by two cognitive systems:
“Contemporary Theories of Intelligence” by James C. Kaufman, Scott Barry Kaufman, and Jonathan A. Plucker, published in The Oxford Handbook of Cognitive Psychology (2013): conclusion
- Traditional IQ models remain influential, but modern theories offer a broader, more nuanced view of intelligence.
- Intelligence is not a single ability but a combination of multiple cognitive, emotional, and adaptive processes.
Future research should focus on integrating psychometric, cognitive, and neuroscientific perspectives.
- Intelligence is not a single ability but a combination of multiple cognitive, emotional, and adaptive processes.
