Intelligence

Intelligence

1. Background, theories and measurement

   • Layperson theories of intelligence
   • Different ideas in parts of the world
     • India: emotion, self-awareness, modesty
     • China: doing what is right, effort in learning
     • USA: practical problem solving, verbal, goal-attainment
     • Big differences within cultures e.g., across life-span and across socio-economical status
   • Historical background to intelligence
     • Galton. Founded psychometrics (the science of measuring mental faculties) and differential psychology. Considered the forefather of intelligence tests. Influenced by his half-cousin Charles Darwin. First to apply statistical methods to the study of human differences and to the inheritance of intelligence.
     • Binet. Set foundation for modern intelligence testing. Asked by French Ministry of Education to devise a method that would determine which children did not learn effectively so they could be given remedial work. Discriminate between capable and less capable pupils, irrespective of their disruptive behaviour. Published the Binet-Simon scale which was the first intelligence test (Glaton had not designed a test. Piaget continued his work.
     • J. M. Cattell. Proposed that intelligence was compromised of 10 basic psychological functions which can be measured scientifically. Devised an instrument to measure these processes called a 'mental test'.
     • Terman. Adapted Binet's test in the USA.
     • Stern. Introduced the term intelligence quotient.
   • Theories
     • Spearman's 'g'
       • Spearman was a student of Glaton. Examind individual differences in information processing, and basic processes such as olfaction and visual-sensory discrimination. Scores on different tests were significantly interrelated. Using factor analysis, Spearman found that scores on tests were significantly related and common variance would be extracted. 'g' = general intelligence factor.
       • Wechsler introduced two tests: The WAIS and the WISC both measure different aspects of intelligence, including verbal and performance tests.
       • Raven argued that intelligence tests should be free of cultural influences, including language and created Raven's Progressive Matrices which rely on non-verbal reasoning problems.
     • Multiple abilities (rather than single factor 'g')
       • Thurstone questioned Spearman's idea of general intelligence and devised multiple factor analysis. He conceptualised 7 primary mental abilities: 1. Verbal comprehension 2. Work fluency 3. Number facility 4. Spatial visualisation 5. Associative memory 6. Perceptual speed 7. Reasoning.
       • Guildford argued intellectual ability can be broken down into several unrelated components and developed the most comprehensive catalogue of human abilites (150 types). This was based on a distinction between operations (5 - cognition, memory, divergent production, convergent production, evaluation), products (6 - units, classes, relations, systems, transformations, implications) and contents (5 - auditory, visual, symbolic, semantic, behavioural).
     • Hierarchical models
       • Vernon incorporated both the general factor ('g') and independent abilities. This combined Spearman's 'g' and rival multi-component theories.
     • Fluid vs crystalized intelligence
       • R. Cattell applied statistical methods to the study of intelligence (like Spearman) and proposed 3 main components of intelligence: 1. fluid intelligence: the ability to learn new things and to solve novel problems, irrespective of previous knowledge and experience 2. crystalized intelligence; refers to the knowledge and skills that can be used to solve problems related to what one has already learned 3. Gsar: the ability to complete short-term memory and retrieval tasks.
         • Fluid intelligence may better reflect what we implicity think intelligence is than crystalized intelligence. However recently crystalized intelligence has got more attention as it seems to better discriminate between high and low IQ scores than fluid intelligence.
   • Measurement
     • Stadardisation of intelligence scores
       • In the 1960's IQ scores were standardised by using the standard deviation. IQ is represented by a normal distribution with a mean of 100 and a SD of 15. 2SD = 95% of population. 3SD 99.7% of population.
         • To become a member of mensa IQ > 140 (upper 2% of population).
   • Definitions of intelligence
     • Terman. The ability to carry out abstract thinking.
     • Freeman. Sensory capacity, perceptual recognition, quickness or alertness in response
     • Calvin. Ability to learn or adjust oneself to the environment.
     • Haggerty. Sensation, perception, association, memory, imagination, discrimination, judgement and reasoning.
     • Wechsler. A global concept that involves an individual's ability to act purposefully, think rationally, and deal with the environment.
   • Piaget suggests the crucial question was why children of the same age made exactly the same types of mistakes. Instead of using standardised tests, Piaget used individual clinical interview. Abandoned psychometrics and developed a qualitative approach. Developed theory of intellectual development (sensorimotor, preoperational, concrete operation, formal operational). Each stage is genetically determined - children cannot be taught to pass from one stage to the next. Intelligence is a form of adaptation - first an adaptation to the child's direct environment (motor.sensory) and later in life an attempt to structure the world.

2. Sex, race and developmental differences

   • Nature vs. nurture. Sex, race and developmental differences are at the interface of nature vs. nurture influences. Therefore, the study of these factors in relation to intelligence offers unique oportunities to weight the relative influences of nature and nurture on intelligence.
   • Sex
     • Terman used the Binet-Simon test with 1000 school children and found that girls scored higher.
     • Spearman argued that there were no sex differences.
     • Wechsler admitted that in standardising his IQ scale he had taken out items that may have been biased against women.
     • Court presented the first systematic review. This considered 120 studies using the Raven's progressive matrices. Sometimes there was male superiority, sometimes female supriority and sometimes no difference at all.
     • Men have greater spatial abilities: the ability to visualise spatial relationships and to mentally manipulate objects.
     • Women outperform men on verbal ability tests.
       • Hyde & Linn carried out a meta-analysis looking at verbal ability across a range of ages. Women scores high for verbal production, especially in adolescence, but this difference disappeared in adulthood.
     • There are clear sex differences in the distribution of IQ scores. Men are more often found amongst the lowest (below 70) and highest (above 140) scorers, whereas women are more likely to homogenous.
       • Lubinski & Humphreys looked at distributions of IQ and found the SD for males indeed to be 7 points larger than for females.
     • Explanations for sex differences
       • Lynn points out that on average, men have larger brais than women. It is probably more likely that it is not size that is important but the number of fissures and neurons.
         • However, Asian people tend to score higher on IQ tests than white people but have smaller brains.
       • Lynn proposed a developmental theory; girls mature faster than
       • Spatial ability is related to testosterone. Females overexposed to androgens show higher spatial intelligence than control groups. It may reflect evolutionary sex roles, e.g., men as spatial hunter-gatherers.
         • Problem: Male hunter-gatherer who finds his way back home > good spatial ability > reproduce genes > but both sons and daughters inherit the superior spatial genes.
         • Burgess place cell recording – different neurons fire when the animal moves to different areas of a square box – helps create a virtual map. This has been found in humans too. These cells are in the hippocampus. Grid cells are also found in the hippocampus – places a virtual grid across an environment – helps to use own movements to locate itself. Place cells, grid cells and head-direction cells can also work together to help us imagine autobiographical events when we want to remember them. This is how spatial navigation works in the brain.
       • Rilea found that in a mental rotation task men only use the right hemisphere whereas women use both hemispheres of the brain (fMRI studies).
       • Haier et al suggested that men and women achieved intelligence through different areas of the brain. In men, intelligence correlated with mainly grey matter volume. Women have more white matter and fewer grey matter areas associated with intelligence. This may suggest that for men intelligence is more related to information-processing (grey matter), but for women it is more related to association and integration of information (white matter).
       • Levine et al suggest that playing with building blocks, puzzles, and video games is related to spatial skills, and boys spend more time with these toys than girls do. Servin et al suggest that playing with dolls and household objects may encourage verbal and social skills.
       • Men see their strengths as being in logical and spatial ability but women see their strengths as being in language and personal skills.
   • Race
     • Genetic explanations suggest differences in race are unchangeable. Environmental explanations suggest society is unfair towards certain groups. Test bias explanations suggest IQ tests are designed to favour certain groups.
     • Hernstein & Murray made an analysis of the distribution of IQ scores in the US. Caused a huge debate in thr US about whether intelligence is genetically inherited (they claim 40-80% genetic). They looked in particular at the relatively small group at the high end of the bell curve. The gap between this small group of people with high IQ and a big remaining group of people with moderate IQ is getting bigger. IQ is a better predictor of many personal dynamics than education level or parental SES. Their results were highly controversial because they reported that white Americans score 15 points higher than black Americans on the WEIS and 18 points higher on the Stnaford-Binet test and because they suggested that programs should be directed at those with high intelligence to strengthen the 'elite' even more rather than at those with low intelligence. They attempted wo explain their results by suggesting that certain social factors in the US are pushing down intelligence,.
     • Gould was very critical of IQ tests - called IQ tests 'The Mismeasure of Man'. Believes the human mind and its intelligence are far too complex to summarise in just one number (the IQ score). It is human tendency to try and make complex things simple but intelligence isn't simple and shouldn't be treated as such.
   • Developmental
     • Intelligence means different things at different ages: in infancy intelligence consists of perceptual and motor abilities, changing to more abstract thought.
     • Spearman proposed that the relationship between abilities may not be constant. He proposed 'law of diminishing returns' or 'ability differentiation hypothesis' which predicts that the positive correlations among different cognitive abilities is weaker among more intelligent subgroups of individuals. Correlation between 12 cognitive tasks in children was .47 for typically developing but .78 for lower ability children.
     • Schaie suggested early childhood sees modest gains on tests of numeracy, verbal recall, verbal ability, inductive reasoning, and spatial orientation. Middle adulthood is a fairly stable period. Late adulthood may see a reduction in fluid intelligence, but not crystalized. Some abilities show a robust decline e.g., reaction time and processing speed and working memory, but not short-term memory.

3. Nature vs nurture

   • Genotype vs phenotype
     • Genotype: an organism's full hereditary information (DNA sequence).
     • Phenotype: the observable characteristics of an individual resulting from the interaction of its genotype with the environment.
     • Two organisms with identical genotypes normally differ in their phenotypes (MZ twins).
     • Heritability estimate (HE): the proportion of the total variance in a trait that can be explained by genetic variation. HE for intelligence is between .5 and .7.
   • Brain plasticity
     • Rosenzweig et al. "Do environmental factors such as a rich or impoverished environment affect the development of neurons in the ceerebral cortex?". Rats lived for 30-60 days in either enriched or impoverished environment. Findings revealed an increased weight of brain and an increased thickness of cortex especially neurons in the cerebral cortex associated with transmission of acetylcholine which is an important neurotransmitter for learning and memory.
       • Follow-up studies indicated that just 2 hours a day in an enriched environment produced the same changes in the brain. This study overturned the conventional wisdom that the brain reaches full maturity in childhood and that brain weight cannot be influenced. The implications of this study mean that poverty (lack of access to good education) may impair brain development.
   • Family, adoption and twin studies
     • When determining the heretability of intelligence, we must consider that the selection of partners is non-random. We may choose partners of similar genetic characteristics e.g., height, colour and intelligence (correlation between partners = .40). The children have similar IQs because the IQs of the parents were already similar: favours estimates of genetic influence. This may shape evolution: brighter parents have brighter offspring. In addition, people with lower IQs have more children so this may alter the distribution of IQ scores. Assotative mating causes IQ correlations between family members to increase over generations. Genetic differences between DZ twins have been progressivly reduced through assotative mating: the remaining 50% of genes is pretty similar too.
     • Lifespan changes
       • Correlations in IQ between MZ twins increases with age.
       • IQ-related genes may only activate in late childhood or adolescence, such that genetic effects early in life "snowball" during development.
       • Effects of genes increase over time while effects of upbringing decrease over time.
   • Nurture: environmental influenced on intelligence
     • Bouchard & Segal listed 21 environmental factors relating to intelligence which were purely correlated
     • The American psychological Association task force identified 4 main types of factors: biological variables and maternal effects (nutrition, lead, prenatal factors), school and education, family environment (birth order, family size), culture (decontextualisation, quatification, biologisation).
       • Nutrition
         • Oddy et al followed 2000 children from birth to age 8 and found that stopping breast feeding early (<6 months) was associated with reduced verbal intelligence.
         • Benton & Roberts found that children given a vitamin-mineral supplement showed increased IQ scores on a measure of fluid intelligence.
         • Qian et al looked at the effects of iodine, and revealed IQ scores 8.7 points higher in groups who had received iodine supplements.
       • Lead
         • McMichael et al exmained the relationship between body lead burden and pregnancy outcome near the largest lead smelting facilities in Australia. IQ scores were negatively correlated with lead concentration at 2, 4, 7, 11 and 13 years of age, also when controlling for maternal intelligence and SES.
       • Prenatal factors
         • Babies with low birth weight and babies suffering from foetal alcohol syndrome show reduced intelligence. Women who smoke later in their pregnancy have children who score lower on IQ regardless of factors such as SES, education and mother's age.
       • Education
         • Kaufman & Lichtenberger conclude that the average correlation between intelligence and school achievement is .50.
         • Ceci found that children who attend school regularly score higher than those who attend less regularly. Intelligence test scores decrease over long summer holidays, and delays in children starting school reduce intelligence scores.
       • Decontextualisation: the ability to disconnect or detach oneself from a situation and think abstractly and then generalise about it. This has developed due to industrialisation in western cultures.
       • Quatification: the act of discovering or expressive the quantity of something - we may do this too much in western cultures.
       • Family environment
         • Belmony & Marolla collected data using the Raven's progressive matrices and showed that children from larger families had a lower IQ even when controlling for SES. Within each family size the first born child had a higher IQ with declining scores with rising birth order.
           • Birth order and intelligence is explained by 2 possible methods: 1. Resource dilution model: parental resources are finite, and therefore as the number of children increases the resources are depleted. 2. Confluence model: first born has an advantage of some time of not sharing parents' attention. Older siblings look after younger siblings and explain things which promoted intelligence. First borns spend more time hearing proper language (from parents), later siblings listen to siblings who speak poorly.
       • Contradicting genetics: the Flynn effect. Flynn gathered large sets of cross-cultural and longitudinal data on intelligence. Found an increase in IQ score of 15 points every 50 years. Most increases have been found in tests of fluid (nonverbal) rather than crystallised intelligence, which means they are not due to educational factors. Possible explanations include length of schooling (people are attending school longer), test-taking sophistication (knowledge and experience of taking tests was not common when tests were first introduced), child rearing practices (parents today are more interested in children's intellectual development) and the technological age (more used to processing visual information). Flynn's own explanation for IQ increase suggests that only recently have people learned to take the hypothetical seriously. Nowadays people show much more willingness to go beyond the concrete world into the abstract world.

4. Creativity

   • Creativity: the process of creating something that is both original and worthwhile.
     • The universal factor in definitions of creativity seems to be novelty. Novelty must be coupled with appropriateness.
   • Different perspectives from which to study creativity
     • Behavioural: novel observable products, associations insights.
     • Biological: physiological correlates, evolutionary brain function, hemispheric activity.
     • Clinical: abnormal behaviour, mental disorders.
     • Cognitive: cognitive processes, attention, flexibility, learning.
     • Developmental: life span changes, family, birth-order, gender differences.
     • Educational: teaching styles, assessment methods, learning, knowledge acquisition.
     • Differential: linked to personality, intelligence (assessment, testing performance).
   • Brain function and creativity
     • Popular pscyhology states that the right hemisphere is creative and the left hemisphere is analytic however most studies indicate both hemispheres contribute to both processes, though the right hemisphere may dominate in creative thinking.
     • Beaty et al formed a robust prediction of individual creative ability from brain functional connectivity. In this study subjects were shown an everyday object and given 12 seconds to come up with the most creative use for that object and given 12 seconds to come up with the most creative use for that object they could think of. The responses were ranked by originality and creativity. Main findings: no single "creative" part of the brain has been revealed but novel thinking seems to engage a broad configuration of brain regions that don't typically work together. Creative thought is reflected by how effectively different regions in the brain that usually work seperately can communicate with each other. Found a synchrony between 3 distinct brain networks: 1. Default network 2. Executive control 3. Salience network. It requires flexibility to be able to engage all 3 networks, which don't typically work together.
       • The researchers were able to predict how creative a person is on the basis of the strength of the connections between the 3 brain networks in the fMRI recordings.
   • Dissociations between creativity and intelligence
     • Unfocussing (daydreaming) may allow a creative solution to pop up.
     • Expertise may hamper creativity.
     • Blockade e.g., writers block (intelligence blockade is rare)
     • Drugs may specifically enhance creativity
     • It is always unexpected, not planned > subconsciously.
     • Divergent rather than convergent thinking.
     • Open-mindedness
   • Testing creativity
     • The alternative uses test (divergent thinking). Scored in fluency (number of items produced) but also originality, flexibility, elaboration and appropriateness.
     • Remote associations test (e.g., identify a forth word associated with...)
     • Consequences test (e.g., imagine what might happen if laws were abolished.
     • Word associations test (e.g., write as many meanings as you can for the word 'bridge')
     • Torrance test of creativity and thinking: divergent production of semantic units (e.g., name all the things you can think of that are red and edible), alternative relations (in what ways are dogs and cats related), and production of systems (write as many sentences as you can using the workd 'rain, station and summer'). Scores are significantly correlated with creative achievement measures.
   • Creativity and intelligence
     • Sternberg and O'Hara considered 5 possible ways in which creativity and intelligence may be related
       • 1. Creativity as a form of intelligence
         • Binet's early attempts to devise an IQ test included open-ended items to measure imagination
         • Sternberg & Lubart argued that there is a clear component of intelligence in creative thinking
       • 2. Intelligence as a form of creativity
         • Creativity is seen as a precondition for intelligence in Sternber & Lubart's investment theory
         • Sternberg proposed that 3 aspects of intelligence underlie creativity: 1. synthetic intelligence: used to combine different congnitions and produce novel associations 2. Analytical intelligence: allows creative individuals to judge the value of an idea 3. Practical intelligence: important for selling ideas to others.
       • 3. Intelligence and creativity as identical constructs
         • This would require scores on creativity and intelligence measures to be highly correlated.
         • Weisberg and Alba argued that no qualitative differences exist.
       • 4. Intelligence ans creativity as unrelated constructs
         • If a response is intelligent it cannot be creative and if a response is creative it cannot be intelligent. This would be demonstrated by low or non-significant correlations between creativity and intelligence but most findings show significant correlations.
       • 5. Intelligence and creativity as overlapping constructs
         • Barron administered divergent thinking and cognitive ability tests to a wide range of participants. The correlation was .40. However, when IQ was higher than 120 there was poor correlation with creativity. Other studies have reported variable correlations ranging from -.05 to .30.
         • The threshold theory of creativity and intelligence implies that a minimum level of intelligence is required to be creative.
         • Guilford & Christensen found that students with lower intelligence were less creative but that those with higher intelligence were neither higher or lower in creativity.
         • Renzulli proposed the three ring theory of giftedness which suggests creativity, IQ and task commitment all lead to a certain amount of giftedness when combined.
   • Creativity and personality
     • King et al found that verbal creativity was significantly associated with openness to experience and extraversion. Openness was the most significant predictor.
     • Feist looked at factors that distinguished creative from less creative scientists and the most important factors were openness and extraversion.
   • Validating intelligence
     • Educational outcomes

5. Emotional intelligence

   • Different aspects of social/emotional intelligence are captured by: AQ (autism quotient), SQ (systemising quotient) and EQ (empathy quotient). These were not designed to test intelligence at all, it is not an ability per se.
     • AQ (autism quotient)
       • Baron-Cohen et al brief, self-administered questionnaire for measuring the degree to which an adult with normal intelligence has traits associated with the autism spectrum. High scorers show more 'autistic-like' traits than low scorers. A score >32 could be indicative of Asperger syndrome but usually not. However, individuals diagnosed with Asperger syndrome almost always have AQ score >32. Thus, those with Asperger form a subset of all those with high AQ scores. High A scorers may have a non-harmonious IQ profile. The AQ comprises 5 sub-components: 1. Social skills 2. Attention switching 3. Attention to detail 4. Communication 5. Imagination
     • EQ (empathy quotient)
       • Baron-Cohen & Wheelwright breif, self-report questionnaire. Low scorers show more 'autistic-like' traits than high scorers. Women score significantly higher than men.
     • SQ (systemising quotient)
       • Baron-Cohen et al high scorers show more 'autistic-like' traits than low scorers. Males score higher than females especially in maths, physics and IT.
     • EQ vs SQ
       • Baron-Cohen the extreme male brain theory of autism
   • Thorndike's social intelligence
     • Thorndike proposed 3 facets of intelligence: 1. Mechanical intelligence: the ability to manage concrete objects 2. Abstract intelligence: the ability to manage ideas 3. Social intelligence: the ability to manage people, or to act wisely in human relations. Social intelligence has since been simplified to "the ability to get along with others".
       • Social intelligence may help us understand psychological disorders - the DSM-V's conceptualization of psychological impairment includes communication, social and interpersonal skills.
       • Thorndike observed that convenient tests of social intelligence are hard to devise and that social intelligence could be found in the nursery, on the playground, in barracks, in factories and salesrooms but it eludes the formal conditions of the laboratory.
         • One of the earliest attempts to measure social intelligence was the George Washington Social Intelligence Test (GWSIT). Scores were significantly correlated with job status, extracurricular activities, and supervisor's work ratings. Scores were also correlated with extraversion and verbal intelligence.
         • Ford and Tisak used multiple measures and identified a psychometrically coherent social intelligence factor in 600 high-school students. Components included: interest and concern for other people, social performance skills, empathic ability and emotional expressiveness and sensitivity to other's emotional expressions.
         • Barnes and Sternberg found two distinguishible aspects: a cognitive component: decoding nonverbal cues and a behavioural component: social competence.
   • William's syndrome: a rare genetic disorder causing mental retardation, an abnormally low IQ, and many health and physical deficiencies. However, children with William's syndrome often have strengths in language and face processing, two vital skills for interacting with people. In contrast, Autism/asperger syndrome is associated with some extremely efficient cognitive abilities, but very poor social intelligence. Indicates that social skills and IQ are distinct abilities.
   • Gardner's multiple intelligences
     • Gardner based his theory on case studies and medical evidence for specific cognitive impairments: dissociation between cognitive and social ability (in conflict with Spearman' G factor).
     • Alzheimer's disease may progressively lead to the decay of cognitive but not social functions.
     • Phineas Gage: the brain regions associated with cognitive operations are independent of those responsible for social skills. He did not have cognitive problems except he did become socially awkward. Left orbitofrontal cortex.
   • The Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT) is a 141 item scale to assess emotional intelligence.
   • Goleman linked emotional intelligence to the amygdala which is involved in aggression and fear (the fight or flight response). Goleman proposed 5 emotional intelligences: 1. Identify one's own emotional states 2. Manage one's own emotional states 3. Emotion related to a drive for achievement 4. Assess and influence other's emotions 5. Sustain good interpersonal relationships.
   • Mirror mechanisms: our brains are mainly designed to interact with other people - they are designed for emotional intelligence, rather than for logical intelligence.
   • In most EQ models, EQ refers to an ability (which you can acquire) however, methodologically and conceptually it assesses a personality trait.
   • Sternberg's theory of practical inteligence: ones ability to find effective solutions, solve problems and apply idea to real life contexts (which is independent from academic ability).
     • Practical intelligence has been equated with the notion of common sense. It involves knowing how to navigate through the problems of everyday life, relying on intuition.
     • Measures of practical intelligence involve situational-judgement inventories.
     • Higher practical intelligence scores relate to higher salaries, better performance ratings, and more productivity.
     • Practical intelligence has been shown to be distinct from general intelligence, crystallized intelligence and aspects of personality such as sociability and self-control.

6. Intelligence and working memory

   • Studies suggest that working memory and intelligence share some variance but that they are not identical constructs. Relationships may therefore occur because performance on both working memory tasks and intelligence tasks rely to some extent on the same cognitive resources.
   • Jaeggi et al published the landmark result: modest increases in performance on an intelligence test following several days of working memory training. This sparked a huge number of studies into working memory training. However, these studies have been heavily criticised and overall, there are mixed findings.