Twin Studies

Question 1

Why are twin studies used?

Answer 1

To see if behaviours are shared by those who are genetically similar

Question 2

What do psychologists look at when they study twins?

Answer 2

The concordance rates meaning the likelihood that if one twin has a certain trait, the other twin will have the same trait

Question 3

What are monozygotic twins? (identical)

Answer 3

they develop from the same egg and are therefore genetically identical and have 100% of the genes in common

Question 4

What are dizygotic twins? (fraternal)

Answer 4

they are two babies who share the same womb at the same time but develop from two separate eggs, they share 50% of the same genes like any siblings

Question 5

If MZ concordance is significantly higher than DZ concordance then

Answer 5

the disorder has genetic componant

Question 6

If MZ concordance is same or similar to DZ concordance then

Answer 6

the disorder is envrionmentally caused

Question 7

If MZ concordance is 100% then

Answer 7

the disorder is genetically caused

Question 8

If MZ concordance is signifcantly less than 100% then

Answer 8

the disorder has an environmental componant

Question 9

Twin studies are experiments which compare the similarity of behaviour between MZ and DZ twins that have been

Answer 9

brought up together

Question 10

Epigenetic modification is when

Answer 10

MZ twins become less identical over time due to the environment

Question 11

Reared apart studies compare the similarity of identical twins who have

Answer 11

grown up together in the same family and those who have grown up in different environments

Question 12

If those who have grown up apart share characteristsics, it can be

Answer 12

more certaintly claimed that those characteristics have a genetic basis

Question 13

In adoption studies, similarities between the participanrt and their biological parent suggest genetic componants whereas

Answer 13

similarities between the participant and their adoptive parents would suggest a role for the environment

Question 14

A weakness of adoption studies is that children are often placed with families similar to their own, therefore,

Answer 14

environmental factors might not be so very different from those of their biological families

Question 15

A weakness of twin studies is that most people are not twins so results of twin studies may not be representative of the development of non twins, therefore

Answer 15

the findings may not generalise to the development of other children or adults

Question 16

In adoption studies, developmental trends can be studied because the studies tend to be longitudinal since ppts can be followed as they develop meaning

Answer 16

characteristics that come about as genes are triggered can be studied (E.g schizophrenia) and linked to genetic factors

Question 17

The usefulness of data from twin studies depends of the instruments used to collect data, e.g

Answer 17

personality/IQ tests which often have questionnable validity and reliability

Question 18

Due to the adoption process, only certain types of people can adopt which means that the environment may not be as different and

Answer 18

many adopted children are brought up in the same way, so environmental factors may affect the results

Question 19

A strength of twin studies is that both twins share the same environment which

Answer 19

acts as a natural form of control over the effects it might have

Question 20

Twin studies are

Answer 20

the main way of studying the effects of genes in behaviour as there is no other way of having identical DNA

Question 21

It is rare for a child to be adopted by a family immediately from birth, so an adoptee may have spent time living with their biological family, before the adoption took pace or

Answer 21

could have spent time in foster care meaning there are possible confounding variables affecting the findings

Question 22

Most people are not adopted meaning that those that are adopted are not representative of the whole population and

Answer 22

there may be something different about mothers or babies that led to the adoptions which could have affected the results

Question 23

Nature refers to

Answer 23

biological causes for behaviour

Question 24

Nurture refers to

Answer 24

the environmental causes of behaviour: this means the importance of upbringing, regardless of who the parents are

Question 25

Adoption studies look at the impact of nurture

Answer 25

on children who are raised by parents who are not their biological parents