Topic 1; Van Leeuwen

Question 1

what is the aim?

Answer 1

to measure the relative influence of assortative mating, cultural transmission, GE interaction and correlation and researchers also wanted to investigate why spouses have similar intelligence scores to one another

Question 2

what was the sample?

Answer 2

• 112 families of twins from the Netherlands about to turn 9
• all had an extra sibling between the ages 9 and 14
• only families without reported psychiatric problems, major medical issues, special educational needs or physical/sensory disabilities were included

Question 3

what was the design of the study?

Answer 3

extended twin design

Question 4

what was the procedure?

Answer 4

• children completed a cognitive test known as Raven Standard Progressive Matrices - the test consisted of 60 problems divided into 5 sets of 12 questions that became increasingly difficult as the test progressed and it covered many cognitive abilities; ranging from identifying missing puzzle pieces and and completing analogies
• adults completed a similar but more advanced test known as the Raven Advanced Progressive Matrices

Question 5

what is phenotypic assortment?

Answer 5

suggests that assortative mating occurs because individuals choose one another they have similar intelligence levels with

Question 6

what is social homogamy?

Answer 6

suggests that because people with similar intelligence levels exist in the same environment, they are more likely to mate with one another

Question 7

what are the SIX findings from this study?

Answer 7

• there were no significant differences between male and female IQ scores
• variance in siblings was significantly larger than twins - suggesting that twins scored similar scores
• cultural/environmental factors had less significance than genetic factors
• higher correlation between the IQ test scores of monozygotic twins
• higher correlation between the IQ test scores of parents - provides evidence of assortative mating (phenotypic assortment)
• children with low IQ scores can be affected more by environmental factors

Question 8

what are the THREE conclusions from the study?

Answer 8

• the main influence on IQ level is genetic factors, but genes can interact with environmental factors to influence intelligence
• cultural transmission does not have a significant influence on IQ levels
• phenotypic assortment better explains spousal resemblance than social homogamy

Question 9

what are the strengths of this study?

Answer 9

• highly ethical; consent was gained from the children’s parents, each IQ test was age appropriate and it is unlikely that participants are at risk of potential metal and physical harm
• high levels of internal reliability; participants completed the tests individually, all information/conditions were the same, meaning that the risk of extraneous variables are reduced plus
• holistic; provides a complex intersection between DNA, phenotypes and environmental factors
• ecological validity - represents exams in an educational setting

Question 10

what are the weaknesses of this study?

Answer 10

• socially sensitive, especially when suggesting that men are more intelligent than women
• deterministic; suggesting that intelligence is largely influenced by genetics may limit the individual’s potential within the educational system
• lacks external validty; only measures fluid intelligence (educational setting) ignores how intelligence is important in other areas such as job employment (self discipline and knowing how to be motivated in orfer to succeed)