Intelligence - The Role of Heredity and Environment in IQ

Question 1

What does IQ stand for?

Answer 1

Intelligence Quotient

Question 2

What is IQ?

Answer 2

Index of an individual’s intelligence

Question 3

What are the two tests for IQ?

Answer 3

Verbal

Non-verbal

Question 4

What are the advantages of non-verbal tests?

Answer 4

Eliminate issues with language, verbal abilities and cultural differences (not 100% of the time)

Question 5

What did Francis Galton believe?

Answer 5

Reasoned intelligence is a product of natural selection

Genetically determined

Potential in theory of evolution for planned betterment - selective breeding

Intelligence = desirable characteristic

Question 6

What did Binet and Simon do?

Answer 6

Developed 1st IQ tests to measure student abilities for education purposes

Question 7

What did Lewis Terman and Maud Merrill do?

Answer 7

Developed Stanford-Binet scale

Studied sample of “gifted” children throughout their lives (longitudinal study)

Highly intelligent individuals not weaklings and misfits but healthy and stable

Question 8

What did Lewis Terman do?

Answer 8

Military use (alpha, beta test) to assign soldiers to tasks appropriate to their abilities during WW1

Non-verbal test

Eugenics - promote selective breeding to cultivate desirable characteristics (intellectually and physically)

Question 9

What did Cyril Burt do?

Answer 9

Advised British government to use aptitude tests to determine which children will go on to grammar schools (11+)

Research seemed to suggest occupational levels and social class determined by innate and hereditary levels of intellignece

Problems with his data and analysis - fabricated?

Question 10

What are the issues with IQ tests?

Answer 10

Cultural bias in test construction and standardisation procedures

Intelligence tests favour groups from more affluent backgrounds and discriminate against less privileged racial, ethnic and social groups

Question 11

What are the more recent IQ tests?

Answer 11

WISC = Wechsler Intelligence Scale for Children

WASI = Wechsler Adult Scale for Intelligence

Include verbal and non-verbal tests (tap into both crystalised and fluid intelligence)

Question 12

What is genotype?

Answer 12

Genetic makeup of an organism

Question 13

What is phenotype?

Answer 13

Observable physical properties or an organism

Include organism’s appearance, development and behaviour

Includes both genotype and environmental influence

Question 14

Can we measure genotype or phenotype?

Answer 14

Only phenotype

Question 15

What does performance on IQ tests depend on?

Answer 15

Many factors

Therefore cannot determine how intelligence is determined - cannot isolate genetics

Question 16

What is degree of genetic relatedness?

Answer 16

Looking at people with various degrees of relatedness can give us an understanding of the genetic basis of a concept

Question 17

What kind of distribution does IQ have?

Answer 17

Normal distribution

Typically seen in characteristics that are genetically predetermined

Question 18

What is the atheoretical definition of intelligence?

Answer 18

Intelligence is what IQ tests measure

No theory of intelligence that determines what questions should be included in an IQ test

However IQ tests highly correlate with each other and with other measures (WM, academic performance, problem solving, etc)

Question 19

What is correlation?

Answer 19

Statistical test and term that examines relationship between 2 or more variables

Question 20

What does the theory that intelligence is a singe construct believe?

Answer 20

Generalised intelligence

Measures
- Stanford-Binet
- Raven’s Progressive Standard matrices

Question 21

What is generalised intellignece?

Answer 21

Single construct that influences all cognitive function

Demonstrated through correlations of performances on different tests

Question 22

What does the theory that intelligence is a multiple construct believe?

Answer 22

Composed of fluid and crystallised intelligence

Supported by correlations between tests of FI and CI respectively

Both interact in some ways

Relatively stable FI but increasing CI across life span

Question 23

What is fluid intelligence?

Answer 23

Cognitive functioning component not influenced by the environment and fixed throughout lifetime

Question 24

What is crystalised intelligence?

Answer 24

Stored factual information which benefits from schooling can change throughout life span

Question 25

How is tested whether intelligence is genetically determined?

Answer 25

Twin studies - valuable to examine genetic characteristics - however hard to separate genetic and environmental factors Degree of genetic relatedness - examining individuals with varying levels of shared genes can help us pick apart genetic influences

Question 26

What are the environmental factors of intelligence?

Answer 26

Environment in the womb Family environment

Question 27

How does the environment in the womb affect intelligence?

Answer 27

Mother's health and habits can influence fetus development

Question 28

How does the family environment affect intelligence?

Answer 28

An enriched and stimulating environment correlates with IQ

Question 29

What was the method of Elardo et al's (1975) study into the quality of family environment?

Answer 29

When speaking to children, mother's voice conveys positive feeling Mother structures child's play periods Mother reads stories at least 3 times weekly Family provides learning equipment appropriate to age of the child Child gets out of house at least 4 times a week Mother shouts at child relatively infrequently Mother spontaneously vocalises to child relatively frequently Children observed at 6 months and 24 months IQ tested at 3 years and 4.5 years

Question 30

What were the results of Elardo et al's (1975) study into the quality of family environment?

Answer 30

Rating of family when child was aged 24 months correlated with IQ at 3 years = .70 Rating of family when child was aged 6 months correlated with IQ at 4.5 years = .44

Question 31

What are the important things to consider when deciding if intelligence is genetically or environmentally determined?

Answer 31

Covariance between inheritance and environment - intelligent children tend to have intelligent parents who provide enriched environment Transactional process - intelligent children provoke an intelligent response that potentially feeds their development even further Isn't possible to specify which part of performance is due to heredity and which is due to environment Estimates of heritability are based on population data and don't necessary apply neatly to individual cases

Question 32

What was the Benton and Roberts (1988) study into whether taking vitamins can make you smarter - boost executive functions?

Answer 32

Study with 6 year old children 50% = vitamin supplement every day for 3 months 50% = placebo IQ measured before and after study Children in experimental group had greater IQ increase compared to control

Question 33

What was the Benton (2001) study into whether taking vitamins can make you smarter - boost executive functions?

Answer 33

Increase only observed in children with really poor nutrition Children that have healthy lifestyle and rich diet didn't benefit

Question 34

What was the Eysenck and Schoenthaler (1997) study into whether taking vitamins can make you smarter - boost executive functions?

Answer 34

Metanalysis Hard to draw conclusions as different studies use different populations, vitamins and IQ tests

Question 35

What was the Owen et al (2010) study into whether cognitive (brain) training can make you smarter or increase cognitive abilities?

Answer 35

430 participants Five cognitive domains (reasoning, memory, planning, visuospatial skills, attention) 6 week training period Participants become better at cognitive task they trained on Effects didn't transfer or generalise to other tasks and to everyday cognition

Question 36

What is the confluence model (Zajonc, 1976) about why 1st born children may be smarter than their younger siblings?

Answer 36

First born children spend more time with intelligence adults As number of siblings increases, children spend more time with each other Interactions between children not as intellectually stimulating as between child and adults

Question 37

What is the dilution model (Blake, 198176) about why 1st born children may be smarter than their younger siblings?

Answer 37

Parental finite resources First or alone child spends significant time with adults, gets more attention As number of siblings increases, time parents spend with each child decreases Less stimulating environment

Question 38

What is the Flynn effect?

Answer 38

IQ is increasing with time in the world IQ maybe 25 points higher for a test designed in 1930s (even fluid intelligence) Can't be evolutionary - not enough time Improvements in education, nutrition and supportive parenting styles