Twin studies
there two types of twin, the MZ(monozygotic twins) and the DZ(dizygotic twins). Twin studies are used to see if behaviour is a genetic cause. So psychologist do this by looking at the concordance rate between the MZ and the DZ twins. If the concordance rate is higher in the MZ twins then it can be said that behaviour is a genetic cause. They also look at twins who were reard apart from each other in other to establish the genetic and environmental cause on behaviour.
Adoption studies
Adopted children share the same genes with their biological parents but they share the same environment with their adoptive parents. Psychologists look at adopted children and their biological parentsto differentiate between genetic and environmental causes on behaviour.
Strengths of twin and adoption studies
- both method are effective in testing the cause of behaviour
- twin studies help to understand some genetic related illnesses like schizophrenia
- the research can be carried out again in order to test its reliabilty
Weaknesses of twin and adoption studies
- the studies are not very reliable as many variables could have affected the results
MRI scanning technique
- this is a structural scanning technique
- it is used to show the damages and tumours in the brain
- a dye is injected into the patient
- and then the patient is scanned
- images are then displayed on the computer showing the image of the brain
- with the darker sides referring to the damaged area
PET scanning technique
- this is a functional scanning technique
- it is used to see the changes in a working brain
- a radioactive chemical is injected into the patient
- the patient is passed through the scanner
- the scanner then picks up the radiation of the chemical
- the draker or warmer places are places with more activity
Use of animals in research in labs
- animals are used to study genes and nrevous system
- when studying genes, their genes are arrnaged to be similar to human genes
- in a lab the variables are controlled making it easier to carry out research
strenghts
- low demand characteristics, animals are not awrer they are taking part in a study
- extraneous variuables are controlled making results experimentally valid
- it is easier to control animals than humans
- animals are not harmed on purpose
- animals produce their offspring on a faster rate than humans
- it is more ethical to harm an animal than human
- psychologists who carry out reesearch on animals abide to the guidlines
weaknesses
- animals may die from the research
- some animal specie are threatned and reduce their number
- animals do not have the right to withdraw
- it can be unethical because animals are harmed