research methods: twin studies - gottesman & shields

Question 1

what is ‘nature’?

Answer 1

• biological causes of behaviour, link to genes, inherited from parents

Question 2

what is ‘nurture’?

Answer 2

• environmental causes of behaviour, shows importance of upbringing

Question 3

what are monozygotic twins?

Answer 3

• identical
• share 100% of genes as they come from one fertilised egg
• dna is 100%
• always the same sex
• if a characteristic is genetic the mz twins should show that characteristic. no characteristic is shared completely by mz twins - there is always some influence from the environment

Question 4

what are some important points to consider about mz twins?

Answer 4

• do not share the same environment, even in the womb they tend to develop differently despite dna being same
• from the start there are some differences between mz twins, such as fingerprints
• some characteristics that are genetic are triggered by environment, so identical twins can become less identical over time, although dna doesn’t change
• epigenetic modification: over time, different environmental influences affect which genes are switched on and off. younger mz twins have few epigenetic differences. 50 year old mz twins have over 300 times the epigenetic differences compared to young mz twins
• some characteristics, such as iq and personality might become more alike as the twins age