[SJH128]

So i'm doing this exam next tuesday and I was just wondering if anyone could help me with these questions for it?

- Strengths and weaknesses of twin studies
-Strengths and weaknesses of adoption studies

And if anyones doing their key issue as 'Are tansgender operations ethical?' what sort of things are you going to talk about and evidence wise.

Thank you!

Also I thought we could use this thread just generally to talk about the exam and help each other

[Rizzy J]

Twin studies

Strength
Reliable- influence of genes on behaviour has been demonstrated and repeatedly in research, eg: genes affecting intelligence, personality, and mental health. Same results have been found time and time again making it realiable
Ecological validity/Generalisability/Application- Twin research is a natural way of investigating the importance of genes and environments in personality and behaviour. Take advantage of this natural situation and use it for research purposes, as twins are the only humans who have share 100% of the same genes.
Internal Validity- Best design would involve twins who have been separated at birth and brought up in different environments allowing us to determine the extent to which genes impact behaviour

Weaknesses
Internal Validity- MZ twins may be treated more similarly than DZ twins because they are identical. Adults treat them as the same person as they cannon tell them apart leading to the twins having similar life experiences. Sharing a similar environment as well as having identical genes leas to the increased similarity between MZ twins compared to DZ. Difficult for the researcher to establish if genes or environment are affecting behaviour.
Reliable/Validity- Usefulness of twin research depends on the tests used to assess characteristics. Often personality tests and IQ tests are criticised for not being reliable and valid which means twin research which uses them may also be invalid.
Application- MZ and DZ twins share a prenatal environment(womb) but experience it differently. Often one takes up space more than the other and maybe squash them. May cause them to develop differently and makes it hard to separate the effects of nature and nurture after they are born.

[Rizzy J]

Adoption studies

Strength
Adoption studies provide us with the most direct comparison of the influences of the environment and genetics because the child is from a different environment and parents so if they are like their biological parents it's genes and if it is their adoptive parents it's environment, by looking at similar characteristics of both parents
Adoption studies can investigate a range of variables and use varied samples and methods. These can include trans-racial adoption and meta analyses. Similarity of finding across different approaches suggests the technique is valid

Weaknesses
Most people are not adopted. Biological mothers of adopted children may not be typical mothers because they may not be fit/well enough to bring the child up. May be more likely to suffer from mental disorders such as depression which they may pass on to their children. Samples may not be generalisable and therefore findings of research not valid.
Often adopted children are placed with families that are similar to their own. Makes it difficult to separate the influences of environment and genes.

[SJH128]

Thank you so much thats really helpful!

[Rizzy J]

http://www.thestudentroom.co.uk/show....php?t=2009596
this thread is the "real one" if you want some more help x