Intelligence Flashcards
What is Gottfredson 1997 definition of intelligence ?
: “Intelligence is a very general mental capability that, among other
things, involves the ability to reason, plan, solve problems, think abstractly, comprehend complex ideas, learn quickly, and learn from experience. It is not an academic skill, rather, it requires a broader and deeper capability for comprehending our surroundings,
‘catching on’, making sense of things, or ‘figuring out’ what to do.”
Galton (1869)
- higher intelligence
- 3 measures (R,S,C)
- nature vs nurture
- Higher intelligence is caused by superior
qualities passed down by heredity - there are individual
differences in intelligence, and it is
possible to measure intelligence directly
Galton measured intelligence
– reaction time
– keenness of sight and hearing
– the ability to distinguish between colours - Galton was the first to differentiate between
the influences of nature and nurture
Binet (1905)
- Binet-Simon Sclale
- Binet-Simon scale (1905): first intelligence test aiming to identify
children who might require special
education - 30 tasks related to everyday life, e.g., Ø following light with eyes, naming parts of the
body, counting coins, recalling a number of
digits, filling in missing words in a sentence - Test results determined the child’s “mental age”
Stern (1912)
- (IQ)
- Stern developed the idea of an Intelligence Quotient (IQ)
- Mental age varied among children
proportionally to their real age - The ratio mental age : chronological age was
fairly constant, e.g., 5:6= 0.83, 8:10= 0.8 - He calculated the IQ as
mental age divided by chronological age, multiplied by 100
Terman (1916)
- Revisited Binet Scale
- Revision of the Binet–Simon scale: Stanford–Binet scale (1916)
- Tested > 1,000 children (Binet had only tested 50): far more accurate information on how children typically
scored on intelligence tasks - Representative samples, standardized testing, age norms
Spearman (1904-1921)
- Positive manifold
- two factor theory “g” and “s”
- Positive manifold - the positive correlations between intelligence tests (person does well on one intelligence test they will perform well on a variety of cognitive ability tests)
- He proposed the idea of general intelligence “g”
- Two factor theory included:
- General intelligence factor ‘g’: mental energy
that is required to perform well on intelligence
tests of all types; deeper fundamental
mechanism - Specific abilities factor ‘s’: specific types of
intelligence needed to perform well on each
different task (Vocabulary intelligence, mathematical intelligence, and spatial intelligence are all specific abilities)
Development of standardised test
- Wechsler (1939-1955)
- Wechsler-Bellevue Scale (1939) – standardised
among a sample of 1,500 adults
– Wechsler Adult Intelligence Scale (WAIS; 1955) standardised among 2,000 adults aged 16-75
– Wechsler Scale for Children (WISC; 1955) for
children aged 5-16 - The Wechsler tests are still widely used in clinical settings today
- benefits - all people could take these tests
Deviation IQ
- Wechsler tested large groups of people to identify norms across different age groups
- The focus was on comparing scores with others of a similar age
- Deviation IQ = actual test score divided by expected score for that age multiplied by 100
- The IQ scores were then transformed and
standardised such that the mean is 100 and the
standard deviation is 15 - approximately 68% of the individuals in the population have an IQ between 85 and 115
Raven’s progressive Matrices (1938)
- culture
- Measure the abstract ability to see relationships
between objects, events and information and
draw inferences from those relationships - the overall IQ score is
based on an individual’s deviation from
standardised norms - It is (supposed to be) free of cultural influences
and language and is often favoured as a good
measure of ‘g’; culture-fair test
Theory of primary mental abilities (1938)
- Thurnstone
- g factor
- Thurstone (1938) challenged the concept of a g-factor. After analyzing data from 56 different tests of mental abilities, he identified a number of primary mental abilities that comprise intelligence as opposed to one general factor.
- The seven primary mental abilities in Thurstone’s model are verbal comprehension, verbal fluency, number facility, spatial visualization, perceptual speed, memory, and inductive reasoning
Fluid vs crystallised intelligence (1963)
- Catell
- Fluid intelligence is your ability to process new information, learn, and solve problems.
- Crystallized intelligence is your stored knowledge, accumulated over the years
Three-stratum theory (1993)
- Carroll
- he says there are three strata
- Stratum III - the general level (g)
- Stratum II - the broad factors
- Stratum I - the specific factors level
- he systematic organisation and integration of over 50 years
of research on the structure of human cognitive abilities
Cattel-Horn-Carrol Theory
- Multi factor theory
- Further integration of existing theories
with practicalities of psychometric testing
in mind
Theory of multiple intelligences
- Gardner 1983, 1996
- challenges the theory of
‘general intelligence
- says that intelligences
– reside in separate sections of the brain,
– are independent of each other, and
– are not controlled by any central
function of the brain
Critique of theory of mutliple intelligence
- Some of the Gardner’s intelligences (e.g., intrapersonal)
are hard to define; whether they are measurable is
questionable - Evidence does not support the existence of separate
neural mechanisms (e.g., Waterhouse, 2006) - Intelligences are intercorrelated with each other highly
and with personality traits (e.g., Furnham, 2009)
Five components of emotional intelligence
- (Goleman, 1995)
- Identify one’s own emotions (self-awareness)
- Managing and controlling one’s emotions (self-regulation)
- Emotional states related to a drive for achievement (motivation)
- Assess and influence other’s emotions (empathy)
- Ability to sustain good interpersonal relationships (social skills)
Nature and Eugenics
- Eugenics is the scientifically
inaccurate theory that humans
can be improved through
selective breeding of populations - The implementation of eugenics
practices has caused widespread
harm, particularly to populations
that are being marginalised
Estimates of heritability
- Plomin (2004)
- Heritability is a measure of how well differences in people’s genes
account for differences in their phenotype - A heritability of 50% means that genes explain 50% of the variation in
intelligence in the population - Plomin et al. (2004): simultaneous analysis of all family,
adoption, and twin data showed a heritability estimate of about 50%
Studying heritability
- Heritability can be studied using:
- Family studies – Assess resemblances between family
members on characteristics of interest as a function of their
degree of relatedness - Twin studies – Behaviours are compared across monozygotic
(MZ) and dizygotic (DZ) twins as a naturally occurring
manipulation of shared genetic makeup - Adoption studies – Comparisons drawn between biological
parents, adoptive parents and adopted children
Issues with heritability of intelligence
- Representativeness
- Complexity of genetic influence
Assortative mating
- Watson (2004)
- tendency to mate with those who are similar to ourselves
- Watson et al. (2004)
– Studied the similarity of 291 newlywed couples
– Measured, e.g., age, religious/political beliefs, education, intelligence - Watson et al. (2004)
– Studied the similarity of 291 newlywed couples
– Measured, e.g., age, religious/political beliefs, education, intelligence
Do intelligent people have bigger brains?
- McDaniel (2005)
– Meta-analysis of 37 studies, over 1,500 individuals
– Positive correlation between brain volume & intelligence of .33 - Pietschnig et al. (2015)
– Meta-analysis of 88 studies, over 8,000 individuals
– Reported a significant, slightly smaller correlation of 0.2
Do intelligent people have a thicker cortex?
- Brouwer
- Shaw (2006)
Cortical thickness shows initial increase at earlier
ages, followed by sustained thinning around
puberty (cf. pruning; Brouwer et al., 2014)
* Shaw et al. (2006):
– Cortical thickness develops differently in highcompared to average-IQ children
– Cortex stayed thicker for longer in high-IQ
children, particularly in frontal areas
Do intelligent people have better neural highways?
- Intelligence is particularly dependent on a brain network that links the frontal to the
parietal lobes (P-FIT: Parieto-Frontal Integration
Theory; Jung & Haier, 2007) - White matter connectivity is correlated with IQ
(Penke et al., 2012) - Age-related deterioration of white matter tracks
correlated with age-related cognitive decline in IQ (Lövdén et al., 2014)
The flynn effect
= the substantial and sustained increase
in intelligence scores over time (on a global level)
- Flynn (1984)
– 73 studies using Wechsler and Standard-Binet tests
(~7,500 participants) from white Americans’
– IQ scores rose between 1932 and 1978
* Flynn (1987, 1994)
– data from 20 countries
– IQ scores were rising yearly across nations
* Nonverbal tests: average increase of ~ 15 points per generation (30 years)
* Verbal tests: average increase of ~ 9 points per generation
- Although the cause of the Flynn effect is still a matter of
debate, it must be due to multiple environmental
factors rather than a genetic shift.
– more recent changes to IQ are unlikely the product of
genetic evolution, the timescales are simply too short
- Two opposing hypotheses have been suggested
– Nutrition hypothesis
– Cognitive stimulation hypothesis
Nutrition hypothesis
- Increased intelligence is part of a nurturing environment that
includes increased height and lifespan, improved health,
decreased rate of infant disease, better vitamin and mineral
nutrition
Cognitive stimulation hypothesis
- Increased intelligence driven by, e.g., improved visual analysis
skills, improved schooling, changes in parental rearing styles,
better-educated parents, smaller families, greater availability of
educational toys
Environmental influences on intelligence
- Neisser (1996)
Neisser et al. (1996) identified four main areas
1. Biological environment (e.g., prenatal environment, nutrition)
2. Family environment
3. School & education
4. Culture
Prenatal environment and nutrition
(Environmental influences on intelligence)
Prenatal environment
Mortensen et al. (2005): Smoking
– Mothers who smoked 20+ cigarettes daily late in their pregnancy were likely to
have children who performed less well on IQ tests at age 18/19
* Mattson & Riley (1998): Alcohol
– Children prenatally exposed to alcohol may exhibit a variety of problems with
memory and attention
– Fetal Alcohol Syndrome (FAS): deficits in, e.g., abstract thinking, planning and
organizing information (Kodituwakku et al., 1995)
Breastfeeding
- Oddy et al. (2003)
– Children (age 8) breastfed for more than 6 months scored 3-6 IQ points
higher on a vocabulary IQ test than did children who were never breastfed - However, maternal intelligence is positively correlated with the
likelihood of breastfeeding (Der et al., 2006) - When controlling for parental IQ or genetics, the effect is much
smaller if at all present (review by Walfisch et al., 2013)
Family size and birth order
Belmont and Marolla (1973)
* Children from larger families had a lower IQ (controlled for social class)
* First-born child always had a better IQ; declining
scores with rising birth order
* Debate around whether effects of family size & birth order are confounded
Culture and intelligence
- Culture as the collective beliefs, attitudes, traditions,
customs, and behaviours that serve as a filter through which
a group of people view and respond to the world
Western and Asian cultures emphasise academic ability, rural
African cultures perceive practical ability as more important - Some Western concepts (e.g., speed when completing tasks)
are unfamiliar in African cultures - cultural differences may affect equal access to the skills and
knowledge required by IQ tests
Cocodia (2014)
Cocodia (2014) compared cultural perceptions of intelligence in
Asia, Africa, and Western cultures
* For instance, in Luo of East Africa people’s notions of intelligence
consists of 4 main concepts:
– Rieko: similar to the Western idea of academic intelligence
– Paro: practical thinking
– Luoro: social attributes (respect, responsibility, consideration)
– Winjo: comprehending instructions
Is IQ culturally biased?
Raven’s Progressive Matrices are often described as a culture
fair or culture reduced test, as it consists of nonverbal items
thereby reducing the language loading of the test
