biological methods Flashcards
what is nature
the effects of your biology (genetics, brain structure)
what is nurture
the effects of your environment ( upbringing, experiences)
what do adoption studies do
compare characteristics between people who have been adopted to different families nature is tested by biological family and nurture by adoptive family
how do you do an adoption study
first - find person with characteristic and who has been adopted
next - compare this person to biological and adoptive families
results - if similar to biological parents its nature and vice versa
what is concordance in an adoption study
means ‘how in agreement / similar things are’ looking for who has a higher relationship shows % of time that child and parent have the trait you are testing
strength of adoption study
- lets you see the cause (nature/nurture)
- control environment
- can be longitudinal
weakness of adoption study
- families that adopt are matched to children so have similar traits
- score is never 100% so must be a combination
- small sample of people available
what is our adoption study
kety
what is the aim of kety
to find if theres a genetic basis for schizophrenia
what is the sample of kety
34 patients with SZ, from danish adoption registry. 3 groups of ps ‘long term sz’ ‘short term sz’ and ‘borderline sz’. matched with 33 controls age gender social class etc.
what are the results of kety
higher concordance between patient and bio family then adoptive family
what is the conclusion of kety
sz is somewhat genetic
what is the method of kety
- used family records to locate relatives
- found 463 relatives and used mental register to assess
- 4 psychiatrists assessed to see if family member had SZ -> blind test ranked same way as patients
- 4 participants were withdrew because no decision could be made about family member
when do you use spearmans rank/rho
ordinal data
looking for relationship
data provides correlation coefficient
strengths of correlations
high in ecological validity
high in mundane realism
findings are applicable to real life
uses existing data so less time consuming
weaknesses of correlation
cant assume cause and effect
does not account for extraneous variables
what can you not establish in a correlation
cause and effect as theres no manipulation of one variable
what is cause and effect
one variable causes the change in the other variable
what is a co-variable
things you measure in a correlation - dont manipulate just measure
what would a scatter graph look like with no correlation
dots everywhere no clear patter
what would a scatter graph look like with positive correlation
both variables increase
what would a scatter graph look like with negative correlation
one variable increases one decreases
what is correlation coefficient
number between 1 and -1 shows the strength and direction of the correlation positive number = positive correlation and vice versa closer to 1 and -1 the stronger
