genetic similarity Flashcards
genetic similarity intro
if we can find out the cause of abnormal behaviours we can find how to treat
if learned from stressful life events, therapy cna help unlearn
if genetics therapy may not help
To understand causes of behaviour – to help with understanding, treating and social attitudes. Potential ethics of findings
if we make assumptions of genetic disorders may have stereotyping
we need to understand the method , why they might make us jump to conclusions
oversimplification of results to make claims,whether theyre robust
insufficent on their own but valuable, provided evidence that smth is genetic
which has allowed next stage of research, e.g molecular genetic
If we are able to find a link between genetic similarity and various disorders, we may be able to look into biological traits ppl have in common, and try and find a specific trait that may trigger such disorders. In doing so, we can help treat others with the disorder and better understand who may become susceptible to such problems.
If we find a link between genetic similarity and disorders, we can find out whether or not its inherited, and identify ppl who may be at risk
holland
holland et al (1988) - p211 on book / p5 on pdf
ANorexia: an eating disorder characterised by someone being extremely underweight. There is intense anxiety and a fear of becoming fat and distorted body image.
Aim- to investigate whether there was a higher concordance rate of anorexia nervosa for monozygotic than dizygotic twins. A difference was sought between MZ and DZ twins. because MZ are 100% genetically identical whereas DZ have only 500/0 of their genes in common. Thus, there should be higher concordance rate for MZ than DZ twins if there is a genetic basis to anorexia nervosa.
Method
opportunity sample of 34 pairs of twins (30 female and 4 male) and one set of triplets was selected because one of the pair (or triplets) had been diagnosed with anorexia.
This was a natural experiment, as the independent variable (genetic relatedness) is naturally occurring and cannot be controlled by the experimenter.
A physical resemblance questionnaire established genetic relatedness, that is, whether the twins were MZ or DZ (16 were MZ and 14 were DZ). MZ twins typically have greater physical resemblance but if there was any uncertainty a blood test was carried out.
This was a longitudinal study, with the researchers checking over time to establish whether the other twin went on to deverop anorexia (the dependent variable).
A clinical interview and standard criteria were used for diagnosis of anorexia.
Findings
A significant difference was found between the concordance rates for identical (MZ) and fraternal (DZ) twins: there was a much higher concordance rate of anorexia for MZ than DZ. twins. Further findings were that in three cases where the non-diagnosed twins didnt have anorexia, they were diagnosed with other psych illnesses, with 2 having minor eating disorders.
Conclusion
Suggests genetic basis for ilnesses such as anorexia and general psychiatric illness.
The fact that the percentage for MZ twins was well below 1000/0 indicates that genes are not wholly responsible.
Thus, genes can provide a predisposition, i.e. they make the individual vulnerable but do not directly trigger the disorder.
if it was 100% due to geneitics there should be 100% concordence
genes strongly implicate beheaviour but cannot say directly
studies show how genes can affect but just correlational??
need to be careful if your family has depression or disorders like anorexia, might be susceptible
Findings suggests there is a shared biological trait between twins that cause anorexia. If we can find out what this is, then we can understand ppl who have this disorder and come up with treatment
