Wk 7 - IQ 1

Question 1

True or false, and why? (x3)

The extent to which genetics affects individual differences in intelligence is influenced by social class.

Answer 1

True
Turkenheimer found heritability estimates were higher for upper-middle classes than lower social classes
Proposed to be because there's less environmental variation in upper-middle class households 
(hence genetics has more “opportunity” to account for individual differences in intelligence).

Question 2

True or false, and why? (x2)
Environmental multipliers could mean that small genetic effects can account for large individual differences in intelligence.

Answer 2

True
e.g. small advantage in intelligence may lead to greater engagement in intellectual pursuits which may foster greater cognitive ability,
Making the variance in intelligence accounted for by the genetic effect large.

Question 3

True or false, and why? (x2)

Based on twin studies cited by Plomin and Spinath (2004), intelligence has been estimated to be about 50% inherited.

Answer 3

True.
The 50% is worked out from the difference between the intelligence correlations of identical and non-identical twins
(.86 and .60 respectively according to Plomin and Spinath, 2004)

Question 4

True or false, and why? (x1)
The difference between monozygotic and dizygotic twin correlations for intelligence increases during development. This suggests increasing genetic influence (according to Plomin and Spinath, 2004).

Answer 4

True

Plotted functions of lifespan IQs diverge over time

Question 5

The US Army Tests of the First World War established the average mental age of white American males as 13.08 years. The MOST significant problem with the interpretation of this statistic is that (x1)
Because… (x1)

Answer 5

An inappropriate standardisation sample was used -
Reference group used for standardization were a group of 62 students and businessmen, defined as having a mental age of 16 (“adult intelligence”).

Question 6

True or false?

Herrnstein and Murray, in their book “The Bell Curve”, used multiple regression techniques to investigate IQ.

Answer 6

True

Question 7

True or false, and why? (x1)
Herrnstein and Murray, in their book “The Bell Curve”, failed to include Socio-Economic Status as a control variable in their analyses of IQ.

Answer 7

False

They did, but it’s been argued they used too crude a measure

Question 8

Name four known correlates of IQ

Answer 8

Family integrity,
Health status,
Academic achievement, and
Law-breaking.

Question 9

True or false, and why? (x2)
The correlation between job performance and IQ is typically in the range .60 to .80, according to Sternberg & Hedlund (2002).

Answer 9

False

It’s between .3 and .6 - range in question is implausibly high

Question 10

True or false, and why? (x1)

The First World War US army intelligence tests were based on GROUP-ADMINISTERED intelligence tests developed by Binet.

Answer 10

False

Intelligence tests developed by Binet were INDIVIDUALLY-ADMINISTERED tests

Question 11

True or false, and why? (x1)
The First World War US army intelligence tests involved a Beta test for recruits who were illiterate in English and a separate Alpha test for recruits who were literate in English.

Answer 11

True

Question 12

True or false, and why? (x1)

The correlation between job status and IQ doesn’t necessarily mean that IQ is a key determinant of job status.

Answer 12

True

Association could be due to some third variable

Question 13

True or false, and why? (x1)

Sternberg and Kaufman (1998) warn of the possibility that IQ and job status are actually uncorrelated.

Answer 13

False
Not saying it’s zero, just warning against assuming that the correlation implies a causal link between IQ and job status.

Question 14

True or false, and why? (x1)
Yerkes, the man behind the First World War US Army Intelligence Tests, argued that intelligence test scores were solely a result of “inborn” intelligence and were not influenced by education at all.

Answer 14

False
Yerkes states, “(The tests) are to some extent influenced by educational acquirement, but in the main the soldier’s inborn intelligence and not the accidents of environment determine his mental rating…”.

Question 15

True or false, and why? (x2)
Some of the tasks used in the First World War US Army Intelligence Tests demonstrated that many recruits had an IQ of zero.

Answer 15

False
True that some of the tasks used in the First World War US Army Intelligence Tests yielded a raw score of zero for many recruits (meaning that they didn’t get any questions correct),
However this was not an IQ score – where an IQ score of zero wouldn’t equate to getting no questions correct

Question 16

What was the difference between Binet (x2) and Yerkes’ (x4) approaches to measuring intelligence, both practically and theoretically?

Answer 16

Binet tested kids in educational contexts, in order to give appropriate remedial action, whereas
Yerkes tested US Army in WWI
With badly designed Alpha and Beta tests,
To match recruits to suitable jobs
(claiming to tap innate/fixed abilities, largely unaffected by education - Binet never claimed such)

Question 17

How could the content of Yerkes’ tests be potentially criticized? (x2)

Answer 17

No way they were language/education free

Question 18

Describe the two components of the WWI US Army IQ tests.

Answer 18

Alpha tests for literates

Beta tests for illiterates and non-English speakers - e.g. maze or pattern completion

Question 19

What was suspicious about the distribution of scores obtained from the WW1 army tests? (x4)

Answer 19

Data for many items had big spike at zero
Beta better than Alpha though
ie many who couldn’t answer/understand the question
Researchers assumed everyone was thick, rather than consider issues of test or administration

Question 20

How was the average mental age of those who completed the WW1 army tests calculated and what was dodgy about this? (x2 and x2)

Answer 20

13.08 years, or 10-12 for ethnic groups
Using a reference sample of students and businessmen, arbitrarily anchored at 16 – at a time when most people never saw high school

Question 21

Describe US eugenics policies after WWI (x5)

Answer 21

Believed genetics eroded by immigration, interbreeding, and lower IQ’s having more children
Immigration quotas for ethnic groups found in WWI data to have low IQ (eg European Jews)
Barred up to 6 million Europeans 1924-39
Compulsory sterilisation for “feeble-minded” and ‘antisocial’ people (e.g. in Virginia, sterilisation law was in place between 1927 and 1971).
Eg Doris Figgins (nee Buck) told she was getting appendix operation, later married, in her 70s found out she’d been sterilised for low IQ test score

Question 22

What are the key arguments put forward in Hernsteing and Murray’s “The Bell Curve”? (x3)

Answer 22

Educational interventions haven’t been successful because intelligence is locked into your genetics
IQ largely inherited (not due to environmental factors, e.g. SES) and hence is relatively invariant (stays similar across the lifespan relative to age group)
Argue that programs aimed at eg deprived kids, even if show small improvement, it’s only temporary

Question 23

What are the counter arguments to those posited by Bernstein and Murray in “The Bell Curve” ? (x2)

Answer 23

Howe: more successful interventions were up to a year, rather than couple of weeks
• Even if a long program, then back in deprivation, hardly surprising scores reverted…
Also, they control for SES using multiple regression – but some have argued that their measure is too crude (parent education x income)

Question 24

What is the evidence for a significant genetic contribution to intelligence and what are the criticisms of this evidence?

Answer 24

Cyril Burt’s studies comparing IQs of monozygotic/dizygotic twins found .7 correlation between identical
Later found to have made up his data (although findings later supported)

Question 25

If IQ is largely inherited, what implications does this have for its mutability? (x1 plus supporting egs x2)

Answer 25

Heritability of IQ has no effect on the extent to which it can be affected by the environment.
Eg short-sightedness and height are both largely inherited, yet both can be improved with interventions such as spectacles and better nutrition

Question 26

What is the Flynn effect (x1)
How did he find it? (x1)
What did he find? (x3)
And what theoretical implications does this have for intelligence test scores? (x2)

Answer 26

Mean IQ has changed over generations
Flynn went back to scores, and standardised against one sample (instead of new ones)
Found huge observed generational score increases
France 1948-78, increased by 22 points
US/UK 1950-80, increased by 15
= evidence for environmental effects on IQ over time
Fears of dilution by foreigners gets even more ridiculous…

Question 27

What are the relationships between intelligence and biological measures?

Answer 27

Correlate between .3 and .4 with simple reaction time, inspection time (e.g. deciding which of 2 lines is longer), and some EEG parameters (see Anderson, 1992).

Question 28

What implications have relationships between intelligence and biological measures been argued to have? (x1)
What are the counterarguments to these arguments? (x2)

Answer 28

People have argued that this indicates IQ represents a fundamental brain process (see Howe, 1997).
However, Howe (1997) notes that even fundamental brain anatomy is influenced by experience (i.e. experience could influence IQ and brain structure)
Our biology is changed by our environment…

Question 29

What real world variables does IQ correlate with?

Answer 29

Academic achievement (.5 to .8)
Job performance (.3 to .6), higher for more complex, unpredictable jobs - IQ claimed to be the “single best” predictor of job success
Socio-economic status
“Quality of life” indices (e.g. health status, law-breaking, family integrity)

Question 30

Why might the relationship between IQ and job performance be spurious, or at least exaggerated, according to Sternberg? (x4)

Answer 30

Sternberg & Kaufman (1998) warn of the dangers of circularity in the IQ/job status relationship (people may already be preselected on the basis of IQ).
Criterion contamination –
ie uni exams are IQ-like, so likely to do better at both, thereby better jobs for higher IQ, sans causation (could just be better in testing contexts)

Question 31

What was the problematic outcome of conclusions drawn from WWI IQ test data? (x1)
Although… (x1)

Answer 31

Eugenics: “We cannot conceive of a worse form of chaos in a real democracy than a population of average intelligence of a little over 13 years.” C. G. Cutten, 1922
Some (see Herrnstein & Murray, 1994) argue IQ tests did not influence eugenics policies as much as has claimed by Gould and others.

Question 32

What conclusion do Bernstein and Murray draw based on their theory of purely inherited intelligence? (x3)

Answer 32

Society will become more and more stratified by intelligence,
With least intelligent (including some racial groups) representing a criminal underclassmay
Who may end up in the equivalent of reservations

Question 33

What is one potential explanation for the growing gender gap in academic achievement?

Answer 33

Peer pressure - among boys, not as cool to be clever

Question 34

What did Plomin and Spinach 2004 find regarding the heritability of IQ? (x5)

Answer 34

.86 correlation between IQ of identical twins - .76 for those raised apart
Only .6 between non-identicals
Points to heritability estimate for intelligence of about 50%
Dizygotic correlation drops away with age - influence of environment over time

Question 35

What are some counterarguments to the undiscredited data on twins’ IQ? (Nisbett 2009) (x6)

Answer 35

Separately reared unlikely to be assigned randomly to very different environments – similar SES/families
Bronfenbrenner (1975/1999) showed that the more similar the environments the higher the correlation between twins - restriction of range (suppressing environmental variance, and hence what it can account for)
Identicals look the same/have similar characteristics – get treated similarly
Shared uterine environment – potentially account for up to 20% of shared variance (Devlin et al 1997)
Influence of genetics differs greatly according to social class - Turkheimer et al. (2003)
Small genetic variance can trigger large environmental influences

Question 36

Explain the effects of social class on heritability estimates (Turkenheimer et al 2003) (x7)

Answer 36

Estimates were much higher for the upper-middle classes than lower social classes
Restriction of range…
Upper middle classes are more homogeneous/at ceiling - most in a good situation
So little variation to show up any effects – genetics is all that’s left to vary
But more environmental variation within the lower SES
So genetics show more in the upper class due to controlling for environment
This DOESN’T mean the environment has little influence.

Question 37

Discuss an example of the ways that small genetic variance can trigger large environmental influences (x4)
What does this mean for small genetic IQ diffs? (x1)

Answer 37

Slight differences in height could trigger interest/motivation for basketball,
Creating feedback loop = much greater advantage than height alone.
Doesn’t mean there’s a basketball gene -
100% of the variance between this basketball star and his classmates is actually genetic
Same with intelligence: slight differences in genetic intelligence might trigger environmental multipliers even though it is just the variance in genetics can technically account for the whole difference.