twin studies

Question 1

what is the scientific name for idenical twins?

Answer 1

• monozygotic twins (MZ)

Question 2

what is the name for non-identical twins?

Answer 2

• Dizygotic twins (DZ)

Question 3

how are MZ twins formed?

Answer 3

• they are conceived in a single egg which later slits
• these twins share 100% genes
• this also means they have to be the same sex
• however development in the womb, eating habits and health can change their appearance slightly.

Question 4

how are Dizygotic twins conceived?

Answer 4

• this happens when two separate eggs are fertilised
• share the same amount of genes as a brother and sister 50%
• can be the same sex or a different sex

Question 5

what is the chance of having in the UK?

Answer 5

1.5%

Question 6

what are twin studies about?

Answer 6

• comparing twins with other twins
• comparing MZ and DZ
• not about comparing twins with non-twins.

Question 7

what would is mean if MZ and DZ twins behaved differently?

Answer 7

• nature most be involved as they are sharing the same environment but are displaying different behaviours.

Question 8

what would it mean if MZ and DZ twins behaved similarly ?

Answer 8

• that nurture was involved as something about the environment/situation they are in is making them act a certain way.

Question 9

what is meant by concordance?

Answer 9

• measures of agreement between twins
• e.g. if both twins shows the same behaviour than concordance is high
• it is normally a % and a high one would be 0.80

Question 10

generalisability?

Answer 10

• not really as twins are rare and twins are needed as the sample, therefore finding may not be applicable to rest of the population
• adopted children may of experienced slightly different things; .

Question 11

reliabilibity?

Answer 11

• multiple births are now increasing which means it is easier for psychologists to carry out twin studies as there is more of them around.
• this makes them reliable as it they are easy to replicate.

Question 12

application?

Answer 12

• it tells us whether important behaviours are down to nature or nurture, e.g. for schizophrenia, knowing this can help with treatment.

Question 13

validity?

Answer 13

• this is an exmaple of where natural occurring variables exist without the need for manipulation from a researcher

Question 14

ethics?

Answer 14

• may draw negative attention to twins highlighting how unusual they are.