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Child Psychology Topics 1-6 Summary Notes (2025 Edition) |
Detailed, Exam-Ready A Guide
Van Leeuwen et al. (2008) – Twin-Family Study of General IQ
What was the main aim of Van Leeuwen et al. (2008)?
To investigate the contributions of shared genetic and shared environmental influences on IQ
variance and to explore reasons for spousal resemblance in intelligence
What was the sample in Van Leeuwen et al. (2008)?
112 families from the Netherlands twin registry each with two parents monozygotic or dizygotic
twins and an extra sibling aged nine to fourteen all volunteers with no reported psychiatric
problems or special educational needs
What was the method used by Van Leeuwen et al. (2008)?
Extended twin family design comparing intelligence test results of monozygotic twins dizygotic
twins siblings and parents with biological data collected via cheek swab and intelligence
measured using Raven’s Progressive Matrices SPM for children and APM for adults
How were the IQ tests administered in Van Leeuwen et al. (2008)?
Children completed the Raven’s SPM individually in separate rooms at their own pace after
verbal instructions while parents completed the APM using written instructions both tests
increased in difficulty and measured general intelligence
What psychometric model was used to analyse results in Van Leeuwen et al. (2008)?
The Rasch model which considers the difficulty of each question and calculates the probability
of scoring high or low based on individual ability so IQ scores were independent of which items
were answered
What were the main findings regarding genetic and environmental influences on IQ in Van
Leeuwen et al. (2008)?
Correlations for IQ were higher in monozygotic twins than in siblings parents or dizygotic twins
supporting a genetic basis for intelligence with genetics accounting for about sixty seven percent
of intelligence and the remainder explained by random environmental factors
What did Van Leeuwen et al. (2008) find about spousal resemblance in IQ?
There was a significant correlation in IQ between couples suggesting that people tend to choose
partners with similar intellectual ability supporting the idea of phenotypic assortment over social
homogamy
,2|Page
What did Van Leeuwen et al. (2008) find about sex differences in IQ?
No statistically significant differences in IQ scores were found between males and females across
all groups including parents twins and siblings
What did Van Leeuwen et al. (2008) find about the impact of environment on children with low
IQ?
Environmental factors were more important for children genetically predisposed to low IQ
showing that gene environment interaction can influence intelligence levels
What overall conclusions did Van Leeuwen et al. (2008) draw?
The main influence on IQ is genetic but genes interact with environmental factors in significant
ways cultural transmission does not significantly influence IQ and phenotypic assortment
explains spousal resemblance better than social homogamy
What are the strengths of Van Leeuwen et al. (2008)?
Large and detailed sample with extended twin family design allowed assessment of both heredity
and cultural transmission use of the Rasch model improved accuracy of IQ measurement and
testing conditions reduced pressure on participants
What are the limitations of Van Leeuwen et al. (2008)?
The sample was unrepresentative being limited to Dutch twin families so results cannot be
confidently generalised to other populations with different ethnic or cultural backgrounds thus
the study lacks population validity
How is Van Leeuwen et al. (2008) relevant to debates in psychology?
The study supports the nature side of the nature nurture debate by showing a strong genetic
influence on intelligence but also provides evidence for gene environment interaction and
addresses issues of assortative mating and cultural transmission
How could Van Leeuwen et al. (2008) be applied in real life?
Findings suggest that children genetically at risk for low IQ could benefit from intellectually
stimulating environments and that understanding genetic and environmental contributions can
help develop practical interventions to improve intelligence
Barkley-Levenson & Galván (2014) – Neural Representation of Expected Value in the
Adolescent Brain
What was the main aim of Barkley-Levenson and Galván (2014)?
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To investigate whether adolescents show greater neural and behavioral sensitivity to the expected
value of rewards than adults and to clarify if adolescent risk-taking is due to brain development
or simply less experience with money
What were the three main hypotheses in Barkley-Levenson and Galván (2014)?
First adolescents would accept more gambles as expected value increased compared to adults
second ventral striatum activation would increase more in adolescents than adults as expected
value increased third adults who behaved like adolescents in gambling would not show the same
hyperactive striatal activation
What was the research method in Barkley-Levenson and Galván (2014)?
A quasi-experiment using an independent measures design conducted in a laboratory setting with
fMRI scanning to measure brain activity during a monetary gambling task
What was the sample in Barkley-Levenson and Galván (2014)?
Participants were adolescents and adults recruited from the community all right-handed with
normal or corrected vision adolescents were aged thirteen to seventeen and adults were aged
twenty five to thirty adults and adolescents were matched on gender and income
How was the gambling task structured in Barkley-Levenson and Galván (2014)?
Participants viewed a series of gambles on a screen each gamble had a fifty percent chance of
winning or losing with varying possible gains and losses they chose to accept or reject each
gamble while their brain activity was measured using fMRI the expected value of each gamble
was calculated as the average of possible outcomes weighted by their probabilities
What behavioral results were found in Barkley-Levenson and Galván (2014)?
Adolescents were more likely than adults to accept gambles as expected value increased
especially for gambles with high positive expected value both groups rarely accepted gambles
with negative expected value showing both could avoid disadvantageous choices
What neural results were found in Barkley-Levenson and Galván (2014)?
fMRI data showed that ventral striatum activation in adolescents increased in proportion to the
expected value of the gamble this effect was stronger in adolescents than adults and persisted
even when groups were matched on income and gambling behavior adults who behaved like
adolescents did not show the same neural activation pattern
What did the study show about the ventral striatum in adolescents?
The ventral striatum in adolescents was hyperactive in response to increasing expected value
compared to adults suggesting a unique developmental stage in the adolescent reward system
that is not simply due to valuing money more because of less experience or lower income
Child Psychology Topics 1-6 Summary Notes (2025 Edition) |
Detailed, Exam-Ready A Guide
Van Leeuwen et al. (2008) – Twin-Family Study of General IQ
What was the main aim of Van Leeuwen et al. (2008)?
To investigate the contributions of shared genetic and shared environmental influences on IQ
variance and to explore reasons for spousal resemblance in intelligence
What was the sample in Van Leeuwen et al. (2008)?
112 families from the Netherlands twin registry each with two parents monozygotic or dizygotic
twins and an extra sibling aged nine to fourteen all volunteers with no reported psychiatric
problems or special educational needs
What was the method used by Van Leeuwen et al. (2008)?
Extended twin family design comparing intelligence test results of monozygotic twins dizygotic
twins siblings and parents with biological data collected via cheek swab and intelligence
measured using Raven’s Progressive Matrices SPM for children and APM for adults
How were the IQ tests administered in Van Leeuwen et al. (2008)?
Children completed the Raven’s SPM individually in separate rooms at their own pace after
verbal instructions while parents completed the APM using written instructions both tests
increased in difficulty and measured general intelligence
What psychometric model was used to analyse results in Van Leeuwen et al. (2008)?
The Rasch model which considers the difficulty of each question and calculates the probability
of scoring high or low based on individual ability so IQ scores were independent of which items
were answered
What were the main findings regarding genetic and environmental influences on IQ in Van
Leeuwen et al. (2008)?
Correlations for IQ were higher in monozygotic twins than in siblings parents or dizygotic twins
supporting a genetic basis for intelligence with genetics accounting for about sixty seven percent
of intelligence and the remainder explained by random environmental factors
What did Van Leeuwen et al. (2008) find about spousal resemblance in IQ?
There was a significant correlation in IQ between couples suggesting that people tend to choose
partners with similar intellectual ability supporting the idea of phenotypic assortment over social
homogamy
,2|Page
What did Van Leeuwen et al. (2008) find about sex differences in IQ?
No statistically significant differences in IQ scores were found between males and females across
all groups including parents twins and siblings
What did Van Leeuwen et al. (2008) find about the impact of environment on children with low
IQ?
Environmental factors were more important for children genetically predisposed to low IQ
showing that gene environment interaction can influence intelligence levels
What overall conclusions did Van Leeuwen et al. (2008) draw?
The main influence on IQ is genetic but genes interact with environmental factors in significant
ways cultural transmission does not significantly influence IQ and phenotypic assortment
explains spousal resemblance better than social homogamy
What are the strengths of Van Leeuwen et al. (2008)?
Large and detailed sample with extended twin family design allowed assessment of both heredity
and cultural transmission use of the Rasch model improved accuracy of IQ measurement and
testing conditions reduced pressure on participants
What are the limitations of Van Leeuwen et al. (2008)?
The sample was unrepresentative being limited to Dutch twin families so results cannot be
confidently generalised to other populations with different ethnic or cultural backgrounds thus
the study lacks population validity
How is Van Leeuwen et al. (2008) relevant to debates in psychology?
The study supports the nature side of the nature nurture debate by showing a strong genetic
influence on intelligence but also provides evidence for gene environment interaction and
addresses issues of assortative mating and cultural transmission
How could Van Leeuwen et al. (2008) be applied in real life?
Findings suggest that children genetically at risk for low IQ could benefit from intellectually
stimulating environments and that understanding genetic and environmental contributions can
help develop practical interventions to improve intelligence
Barkley-Levenson & Galván (2014) – Neural Representation of Expected Value in the
Adolescent Brain
What was the main aim of Barkley-Levenson and Galván (2014)?
, 3|Page
To investigate whether adolescents show greater neural and behavioral sensitivity to the expected
value of rewards than adults and to clarify if adolescent risk-taking is due to brain development
or simply less experience with money
What were the three main hypotheses in Barkley-Levenson and Galván (2014)?
First adolescents would accept more gambles as expected value increased compared to adults
second ventral striatum activation would increase more in adolescents than adults as expected
value increased third adults who behaved like adolescents in gambling would not show the same
hyperactive striatal activation
What was the research method in Barkley-Levenson and Galván (2014)?
A quasi-experiment using an independent measures design conducted in a laboratory setting with
fMRI scanning to measure brain activity during a monetary gambling task
What was the sample in Barkley-Levenson and Galván (2014)?
Participants were adolescents and adults recruited from the community all right-handed with
normal or corrected vision adolescents were aged thirteen to seventeen and adults were aged
twenty five to thirty adults and adolescents were matched on gender and income
How was the gambling task structured in Barkley-Levenson and Galván (2014)?
Participants viewed a series of gambles on a screen each gamble had a fifty percent chance of
winning or losing with varying possible gains and losses they chose to accept or reject each
gamble while their brain activity was measured using fMRI the expected value of each gamble
was calculated as the average of possible outcomes weighted by their probabilities
What behavioral results were found in Barkley-Levenson and Galván (2014)?
Adolescents were more likely than adults to accept gambles as expected value increased
especially for gambles with high positive expected value both groups rarely accepted gambles
with negative expected value showing both could avoid disadvantageous choices
What neural results were found in Barkley-Levenson and Galván (2014)?
fMRI data showed that ventral striatum activation in adolescents increased in proportion to the
expected value of the gamble this effect was stronger in adolescents than adults and persisted
even when groups were matched on income and gambling behavior adults who behaved like
adolescents did not show the same neural activation pattern
What did the study show about the ventral striatum in adolescents?
The ventral striatum in adolescents was hyperactive in response to increasing expected value
compared to adults suggesting a unique developmental stage in the adolescent reward system
that is not simply due to valuing money more because of less experience or lower income
