Language and Thought L9

Question 1

What did the bell curve study claim?

Answer 1

• IQ tests measure what most people think of as intelligence
• Psychologists agree that a general factor (g) exists
• IQ is almost impossible to modify through education and special training
• IQ is mostly genetically determined
• Racial differences in IQ are the result of heredity
• US govt wasting money with enrichment programs

Question 2

Who carried out the bell curve study?

Answer 2

1994, Herrnstein & Murray

Question 3

What is hereability?

Answer 3

A statistical estimate of the genetic contribution of a particular trait

Question 4

What is often used to study the heritability of a trait such as intelligence?

Answer 4

• Twins
• Look at the difference between how similar intelligence is in monozygotic (100%) and dizygotic (50%)
• If mainly genetic monozygotic should be more similar

Question 5

What is a second way to use twins to study heritability?

Answer 5

Spilt the monozygotic twins up, if traits completely determined by genes then the environmental difference should not matter

Question 6

How can adoptive children be used to study heritability?

Answer 6

• Compare adopted children with birth parents versus adoptive parents
• If genetics is key component then should be more similar to birth parents, if environment adoptive parents should have more in common

Question 7

What is found when looking at intelligence using twin studies?

Answer 7

• Monozygotic twins raised together most similar
• Then monozygotic twins raised apart
• Then dizygotic twins raised together
• Then siblings raised together

Question 8

What is the conclusion from twin studies on the heritability of IQ?

Answer 8

Intelligence is partly driven by heritability but the environment also has a part to play

Question 9

What accounts for the difference in intelligence similarity between dizygotic twins and siblings?

Answer 9

• Dizygotic twins more similar in IQ scores despite sharing the same percentage of genes as siblings (50%)
• This because they share the fetal environment

Question 10

What is a limitation of twin studies?

Answer 10

-Assume that environments of identical twins
are no more similar than those of fraternal
twins or siblings
-Due to the fact that identical twins share many of the same genes they are likely to interact with the environment in the same way e.g. have genes for being a good basketball player means more likely to join teams and be surrounded by that kind of environment (have more shared environment)

Question 11

What are some clear examples of genetics influencing IQ?

Answer 11

• Inherited Diseases (PKU, Tay Sachs) → impair development

- Genetic non-inherited influences such as Down’s Syndrome (most cases of Down’s not inherited)

Question 12

What are some clear examples of the environment influencing IQ?

Answer 12

• Teratogens (drugs)
• Nutrition (good helps, bad hinders)
• Stimulation
• Trauma
• Lead
• Mercury (fish)
• Schooling

Question 13

What is particularly interesting about the effect of schooling on IQ?

Answer 13

Children were tested and found that after a summer holiday their IQ dropped. If intelligence was a fixed trait then an environmental effect such as schooling should not have any impact.

Question 14

What was the Abecedarian Project (North Carolina

1970s)?

Answer 14

• Looked at the effect of enriched day care on intelligence scores
• 112 children from deprived backgrounds were randomly assigned to either an intervention or non-intervention group
• Intervention involved full time 1:1 high quality education with a focus on social, emotional, cognitive and language development
• The non-intervention group had a non-stimulating environment
• The advantages of being in the intervention group were seen up to the age of 21 with 70% of the intervention group going on to higher education as opposed to just 40% in the non-intervention group.

Question 15

What do the results from the Abecedarian Project show?

Answer 15

• If intelligence was fixed (genetic) early intervention should not have as much of an effect
• Focusing on language development was particularly important

Question 16

Does high heritability mean intelligence is not influenced by the environment?

Answer 16

No, environmental factors relate to children’s IQ scores

Question 17

Why does race tell us very little about

intelligence?

Answer 17

1. There is much variation and overlap within each
   group
2. Within and between group differences might not
   have similar causes
3. Evidence for environmental effects on differences
   between ethnicities on intelligence scores

Question 18

What most likely is the factor contributing to within group differences?

Answer 18

Genetics

Question 19

What most likely is the factor contributing to between group differences?

Answer 19

Environment

Question 20

What can be inferred from the fact that mean difference in IQ scores between groups is changing?

Answer 20

• Evidence that environment is having an effect
• Is seen when comparing African-American and European-American scores since world was 2 as well as migrant scores
• This can’t be due to a fast evolving mutation(genetics) instead likely due to the change in environment to become more equal between the groups

Question 21

What did the study proving that the environment can influence the development of cognitive abilities involve?

Answer 21

One group : trade
One group : tailors (don’t interact with a lot of people)

Trade group scored higher on intelligence test

Question 22

What was found when African-American children were adopted into families of varying socio-economic background?

Answer 22

-When adopted into high SES (socio‐economic status)
families they showed significantly higher IQ scores than those who remain in lower SES homes
-Demonstrates the effect of the environment

Question 23

Who carried out the studies involving moving African American children to different households?

Answer 23

Scarr & Weinberg, 1976

Question 24

What was found when children were removed from abusive environments?

Answer 24

• All had increase in IQ

- Bigger increase came from more optimal environments

Question 25

When can heritability estimates change?

Answer 25

-Heritability estimates differ depending on SES group
(high versus low)
-In high there is more difference in the similarity between monozygotic and dizygotic twins whereas in low SES there is less of a difference

Question 26

To sum up what is the current view of the factors influencing intelligence?

Answer 26

Genetics provides potential but the right environment is needed for that intelligence to be expressed

Question 27

What did Spencer, Steele, & Quinn (1999) show?

Answer 27

-Demonstrated what is called the Stereotype threat
i.e. Stereotypes have a negative impact on
performance
-Found with both gender and race
-If stereotypes can have an effect then intelligence must not be a fixed/ purely genetic trait

Question 28

What was the structure of Spencer, Steele, & Quinn’s study?

Answer 28

• Investigated the effect of gender on math ability.
• In one group the girls were told that it was gender that influenced their math ability before they were given a test and thus did worse
• In the second group they were told nothing and so they performed just as well as the girls
• What is happening is that they are being primed to view any challenges they face in the test as due to their gender and therefore out of their control (even if not consciously aware)