Section 5 : The Approaches in Psychology - The Biological Approach Flashcards
What are the 3 basic assumptions of the biological approach
- Human behaviours can be explained by looking at hormones, genetics, evolution and nervous system
- in theory we can explain all behaviour using biological causes, unwanted behaviour could be modified or removed using biological treatments e.g. 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
What contains the information that makes us unique
Genes
Genes are important in the development of…
The brain and therefore have a role in our behaviour
What does Darwin’s theory of evolution suggest
- Individual who are better with adapted to their environment through having better genes are more likely to survive to reproduce and pass on their useful genes
- Those who are less well adapted will be less likely to survive and reproduce and pass their genes
- Eventually the less useful genes will be eliminated from the gene pool
- Through of natural selection early humans became better adapted to their environments
According to Darwin’s evolution theory how may have phobias and aggressions evolved
Behaviours such as phobias and aggression may have evolved because of the survival advantage they gave
What is genotype
The genes of a person
What is phenotype
The characteristics of a person that their genes produce e.g. hair and eye colour
What are faulty genes known to cause
Diseases that have some 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, intelligence, personality and sexual orientation
What were type of studies are used to see if genetics has a role in schizophrenia
- Twin Studies
- Adoption Studies
What is the link between identical twins and non identical twin and schizophrenia
- Identical twins share 100% of their genes
- Non identical twins share 50% of genes
- if Schizophrenia has a purely genetic basis and one of the identical twins suffer from schizophrenia then the other twin will suffer from it too
- if schizophrenia has a purely genetic basis and one of the non identical twins suffer from schizophrenia then the other non identical twin’s risk of developing it should be lower
What was Gottesman 1991
Gottesman carried out a meta-analysis of approximately 40 twins
What was the results of Gottesman 1991
- 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
What is the conclusion of Gottesman 1991
Schizophrenia has a strong genetic basis
What were the evaluations of Gottesman 1991
- The meta-analysis was carried out in field studies - gave the research high ecological validity
- because identical twins share 100% of their genes, it might be expected that both would always suffer from the same conditions
- the fact that 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
What adoption study provided evidence for a genetic basis of schizophrenia
Heston 1966 - An adoption study of schizophrenia
What was the method of Heston 1966
- 47 adopted children whose biological mothers had schizophrenia were studied
- the control group consisted of 50 adopted children whose biological mothers didn’t suffer from schizophrenia
- the children were followed up as adults and were interviewed and given intelligence and personality tests
What were the results of Heston 1966
- Experimental group, 5 of the 47 became schizophrenic
- 0 of the 50 were schizophrenic in the control group
- another 4 of the experimental group were classified as borderline schizophrenic by the raters
What was the conclusion of Heston 1966
The study supports the view that schizophrenia has a genetic basis
What are the evaluations of Heston 1966
- Interview data can be unreliable and affected by social desirability bias
- Interviews are a good way of getting data in a naturalistic way
- The adopted children whose mothers didn’t suffer from any conditions might not have shown any symptoms of schizophrenia yet - can’t be completely ruled out
What did psychologists use to investigate brain structure and function before brain scanning techniques were developed
They relied on case studies of people who had experienced a brain injury or had brain operations.
What is the relation between the site damaged and change in behaviour when psychologist looked at case studies of brain injuries
If the person had brain damage in a specific area and also a change in behaviour, the assumption could be made that the two were related
What is a famous case study
The case study of Phineas Gage:
- Iron bar went straight through his head after an explosion
- After the accident he was less organised and more impulsive and increased aggression
- led to believe that this area of the brain is responsible for these behaviours
- case study of one person and so it isn’t representative leads to problems with generalising the results
What were the problems with case studies
- not representative - problems with generalising the results
- these studies aren’t conducted in controlled circumstances - less scientific
- ethically we can’t deliberately inflict this type of brain injury in humans
- Non Human animals have been used to study brain structure and behaviour
- Differences between non human animal brains and human brains mean that results may not be useful when we apply them to human behaviour
What do brain scans help examine
Patterns of brain activity and anatomy
What are the five basic brain scan techniques
- PET scans
- CAT scans
- MRI scans
- Functional MRI scans
- SQUID magnetometry
What are PET scans
- 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 allow us to see where the brain is most active when we are thinking about certain things
- they show average activity over a 60 second period, not by moment by moment
What are CAT Scans
- Scans that detect damaged parts of the brain, tumours, blood clots
- Brain structure is shown not function
What are MRI scans
- Scans that detect small tumours and provide detailed information about structure
What are functional MRI scans
- Scans that provide structural and functional information
What is SQUID magnetometry
- A technique that produces accurate images of brain activity by measuring the magnetic fields generated when neurons are activated
- However outside sources of magnetism can affect measurements
What evidence is there from MRI scans to show changes in brain structure
Maguire et al 2000 - a study of taxi drivers’ brains
What was the method of Maguire et al 2000
- Natural experiment
- MRI scans from 16 licensed male London taxi drivers
- Compared with a control group who had never driven taxis
- All of the participants were in a good general neurological and psychiatric health
- average age of 44
- All of taxi drivers had been working for at least 18 months
What were the results of Maguire et al 2000
- Average size of the right posterior hippocampus was significantly larger in the taxi driver group compared to the control group
- Additionally the increased size was relative to the length of time the taxi driver had been working
- l9nger they’d been working the larger their right posterior hippocampus
What was the conclusion of Maguire et al 2000
- The hippocampus is responsible for storing a spatial representation of the environment
- it seems that the specific navigational demands sin the taxi drivers resulted in physical change
What were the evaluations of Maguire et al 2000
- Findings of the study could be used to help those with brain injuries as it shows that the size of structures within the brain can be influenced through cognitive activity
- Rehabilitation could be tailored to the specific needs of the individuals and their injuries
- Small sample size
- Results can be generalised to male taxi drivers in London
- Results can’t be generalised to other areas of the brain
How was brain structure investigated in aggression
- Bard and Mountcastle 1948 found that lesioning areas of the brains of cats led to changes in levels of aggression
- their research suggests that the hypothalamus and amygdala are involved in aggression
How was brain structure investigated in memory
- Milner et al 1957, case study, found that HM was unable to use his long term memory effectively, suggesting that the hippocampus has an important role here
How was brain structure investigated in psychopathology
Szeszko et al 1995 found differences in the prefrontal cortex when comparing people with and without schizophrenia suggesting a relationship between them
Other than brain structure, what also might influence behaviour
Neurochemistry
What is neurochemistry
Neurochemistry is all about the nervous system and neurotransmitters. The biological approach looks at the role they might play in explaining behaviour
What part of Neurochemistry may produce psychological disorders
- Too much or too little of a particular neurotransmitter may produce psychological disorders
- e.g. an increased level of dopamine is linked to schizophrenia. Drugs like cocaine, which increase dopamine levels, can lead to schizophrenia-like symptoms
What do some biological psychologists investigate
The impact neurotransmitter have on behaviour
What are the strengths of the biological approach
- The approach can provide evidence to support or disprove a theory - its a very scientific approach
- if a biological cause can be found for mental health problems or for unwanted behaviour such as aggression, then biological treatments can be developed to help individuals
What are the weaknesses of the biological approach
- The approach doesn’t take into account the influence of peoples environment, their family, childhood experiences or their social situation.
- Using a biological explanation for negative behaviour can lead to individuals or groups avoiding taking personal or social responsibility for their behaviour
