Approaches To Psychology: Biological Approach Flashcards
Where do genes come from and how do they influence behaviour
At conception, the egg and sperm join up to give a total of 46 chromosomes
Each chromosome is made up of a coil of DNA, which in turn is made up of lots of genes
The genes contain the information that make us unique in appearance (e.g. hair, skin and eye colour)
However, genes are also relevant in psychology, as they are important in the development of the brain, and therefore have a role in our behaviour
What are the 3 assumptions of the biological approach
Human behaviour can be explained by looking at biological components such as hormones, genetics, evolution and the nervous system
In theory, if we can explain all behaviour using biological causes, unwanted behaviour could be modified or removed using biological treatments such as medication for mental illness
Experimental research conducted using animals can inform us about human behaviour and biological influences, because we share a lot of biological similarities
How does Darwin’s theory of evolution explain certain behaviours
Darwin’s theory of evolution suggests that people with better genes are more likely to survive and reproduce and pass on their useful genes
Those who are less well adapted will be less likely to survive and reproduce and pass on their genes
Eventually, their less useful genes will be eliminated from the gene pool for that species
Early humans became better adapted to their environments through natural selection
This means behaviours such as phobias and aggression may have evolved because of the survival advantage they gave
Difference between genotype and phenotype
The genotype of a person is the genes they have
The phenotype of a person is the characteristics their genes produce - e.g. hair and eye colour
How can genetics explain psychological traits
Faulty genes are known to cause some diseases that have psychological effects, e.g. Huntington’s disease that leads to a deterioration of mental abilities
Biological psychologists reckon that genetics can explain “psychological traits”
These are things like gender behaviour (things that men and women do differently), intelligence, personality and sexual orientation
Why do psychologists study genetics and what methods do they use
They study genetics to see which genes make some people more likely to develop things like mental illness or addictions
Twin studies and adoption studies are useful for studying these areas
How can twin studies be used to study mental illnesses
Identical twins share 100% of their genes
So in theory, if illnesses such as schizophrenia has a purely genetic basis and if one twin suffers from schizophrenia, then the other twin will too
Non-identical twins share 50% of their genes, so the risk of both suffering should be lower
Method of Gottesman’s meta-analysis of twin studies
Gottesman carried out a meta-analysis of approx 40 twin studies
Results of Gottesman’s meta-analysis of twin studies
It was found that having an identical twin with schizophrenia gave you a 48% chance of developing the condition
This reduced to 17% in non-identical twins
Conclusion of Gottesman’s meta-analysis of twin studies
Schizophrenia has a strong genetic basis
Evaluation of Gottesman’s meta-analysis of twin studies
The meta-analysis was carried out on field studies, giving the research high ecological validity
Because identical twins share 100% of their genes, it might be expected that both twins would always suffer from the same conditions
Both twins had developed schizophrenia in only about half of the cases means that another factor must be involved
Identical twins tend to be treated more similarly than non-identical twins and so the family environment might play a large role
How can adoption studies be used to study mental illnesses
Adoption studies have provided evidence for a genetic basis of mental illnesses like schizophrenia
Method of Heston’s adoption study of schizophrenia
47 adopted children whose biological mothers had schizophrenia were studied
Control group consisted of 50 adopted children whose biological mothers didn’t suffer from schizophrenia
Children were followed up as adults and were interviewed and given intelligence and personality tests
Results of Heston’s adoption study of schizophrenia
Of the experimental group, 5 of the 47 schizophrenia, compared to 0 in the control group
Another 4 of the experimental group were classified as borderline schizophrenic by the raters
Conclusion of Heston’s adoption study of schizophrenia
The study supports the view that schizophrenic has a genetic basis
Evaluation of Heston’s adoption study of schizophrenia
Interview data can be unreliable and affected by social desirability bias
However, interviews are a good way of getting data in a naturalistic way
The adopted children whose mothers didn’t suffer from any conditions might have not shown any symptoms of schizophrenia yet - it can’t be completely ruled out
What are PET scans
Stands for positron emission tomography
Shows which parts of the brain are active during different tasks
By studying PET scans, we can link certain areas of the brain with particular functions
They also allow us to see where the brain is most active when we are thinking about certain things
What are CAT scans
CAT scans detect damaged parts of the brain, tumours and blood clots
Brain structure is shown, not function
What are MRI scans
They can detect small tumours and provide detailed information about structure
What are fMRI scans
Functional MRI scans provide structural and functional information
What are SQUID magnetometry
They produce accurate images of brain activity by measuring the magnetic fields generated when neurons are active
However, outside sources of magnetism can affect measurements
Positive evaluation of the strengths of the biological approach
It is a scientific approach. Highly scientific methods e.g. fMRIs, EEGs & twin studies lead to reliable data.
Helps establish psychology as a respectable science
Impact of biology on behaviour can lead to treatment and intervention to those suffering e.g. anti-depressants
Understanding how an abnormal brain works can shed light on normal brain functioning
Measurements can be objective and use of complex machinery allows accurate and precise measurements
Negative evaluation of the limitations of biological approach ( what it regards humans as )
It is a deterministic approach as it believes that we are determined by our physiological, genetic or evolutionary make-up.
Thus stating that there is no free will.
Reductionist: all human behaviour can be explained through biological processes and we are not unique
It is also dehumanising to present humans as ‘biological machines’
Biological approach ignores the role of the environment etc. it should be used in combination which is known as the biosocial approach
Negative evaluation of limitations of the biological approach ( how it is carried out )
Research may focus on rare conditions that have little impact on the everyday lives of most people
Complex machinery operated by humans and therefore measurements could be subject to human error
Correlations frequently employed – cannot determine cause and effect
Small or restricted samples make findings difficult to generalise
Laboratory experiments lack ecological validity
How did psychologists study the brain before brain scans
They relied on case studies of people who had experienced brain injuries or had brain operations
If the person had brain damaged in a specific area and a change in behaviour then it’s assumed that the two were related
Case study of Phineas Gage
Damage to frontal lobe after explosion causing an iron bar going through his head
After incident he was less organised and more impulsive, also became more aggressive
Lead to the belief that this area is responsible for these behaviours
However, this is a case study of only one person and so the results are not generalisable to everyone
How do psychologists investigate the brain
Case studies on brain injuries are no conducted in controlled circumstances, less scientific
Also less ethical as we cannot purposefully inflict brain injuries on humans
Non - human animals have been used to study brain structure and behaviour
Differences between non - human and human brains means that the results may not be able to be applied to human behaviour
This is why psychologists use brain scans
