The biological approach Flashcards
how does the biological approach attempt to explain how we think, feel, and behave
as a result of physical factors within the body, such as the nervous system and genetics
3 key assumptions of the biological approach
- human behaviour is explained by physiological processes and structures like hormones, genetics, evolution, and the nervous system
- the brain is the main focus/reason for behaviour: the mind is a result of biological structures and processes
- behaviour can be modified and improved with drugs because it is down to biological processes
why do scientists experiment on animals to explain the biological approach
we share lots of biological similarities
what are genes
sections of strands of dna found in our cells
how do children receive their genes
half from their mother and half from their father
what do genes control
physical processes in the body
true or false, all characteristics come from a single gene
false - some can come from gene combinations
what is the difference between a dominant gene and a recessive gene
dominant genes show their effect even if there is only one copy of that gene in the pair whereas if a person was to display a recessive gene, the person much have the gene on both chromosomes in the pair
what is genotype
the actual set of genes a person has (their DNA)
what is a phenotype
the observable behaviour and physical characteristics of an individuals
do identical twins have the same genotype or phenotype
same genotype, different phenotypes
why are twin studies the most commonly used method of investigating genetics within psychology
if a characteristic or behaviour is genetic, we would expect all identical twins to be 100% concordant, whereas we would only expect non-identical twins to be 50% concordant because they share fewer genes
what is the scientific name for identical twins
monozygotic (MZ)
what is the scientific name for non-identical twins
dizygotic (DZ)
give an example of a twin study used to see is schizophrenia is genetic, and what this suggests/shows
Gottesman and Shields (1966) compared MZ and DZ twins for schizophrenia.
After going through scientific testing, they found a concordance rate for MZ=42% and DZ=9%.
This suggests that there is a genetic component to SZ because concordance rates were much higher from MZ twins compared to DZ twins as they share more genetics.
However, the fact that the concordance rate was not 100% suggests that there may also by an environmental element to the disorder
what is the best way to isolate the influence of genes and the environment in an experiment
adoption studies (child would have the genes of biological parents but environment of adopted parents)
what do adoption studies show
if the adoptee has similarities with their biological parents, genes have an influence on behaviour
if the adoptee has similarities with their adopted parents, the environment has an influence on behaviour
who carried out an adoption experiment to study the role of nature and nurture in Sz (1% chance of getting)
Heston (1966)
What was Heston’s procedure for his adoption study
the study was carried out on children born between 1915-1945 who had been separated from their Sz mothers in their first 2 weeks
it was a matching pairs study, with the control group being children whose mothers did not have Sz - they were matched for their initial time in child-care, sex, and type of eventual placement
in 1964, Heston psychiatrically reviewed all ppts to see if they had Sz
what were the results of Heston’s study and what does this show
10.6% of the experimental group had Sz, whereas 0% of the control group did
this supports a genetic cause of Sz, but it is clear that environmental factors should not be ignored
break down the peripheral nervous system
somatic and autonomic
autonomic -> sympathetic or parasympathetic
break down the CNS
brain or spinal cord (all reactions pass through the CNS before being processed by the brain
what are the 6 parts of the brain
frontal lobe
parietal
occipital
cerebellum
brain stem
temporal
what is the role of the frontal lobe in the brain
used for higher cognitive functions such as memory, emotions, and problem solving (also for speech)
what is the role of the parietal in the brain
sensory perception (mainly touch and pain) - this is home to the brain’s primary somatic sensory cortex
what is the role of the occipital in the brain
decodes messages from the eyes into information that the brain can register
what is the role of the cerebellum in the brain
coordinates movement and balance
what is the role of the brain stem in the brain
used for unconscious actions like breathing, heart rate, blood pressure etc.
what is the role of the temporal in the brain
used for auditory processing and recognising language
how do PET scans work
uses a radioactive chemical which shows which part of the brain is most active when thinking about different things
how to CAT scans work
shows the outside structure of the brain so can be used to tell which part is damaged
how to MRI scans work
provides detailed information about brain structure
how do fMRI scans work
provides detailed information about the brain function and activity
what does neurochemistry refer to
the action of chemicals in the brain and how these lead to thoughts and behaviour
what are neurotransmitters
chemical messages that travel from one neuron to another across a synapse
what are excitatory neurotransmitters
NT’s that trigger nerve impulses in the post-synaptic neuron, and stimulate the brain into action
what are inhibitory neurotransmitters
NT’s that limit nerve impulses in the post-synaptic neuron and have a calming effect on the brain
what does evolution refer to
the gradual changes/developments in inherited characteristics in a population over many successful generations
what did Charles Darwin suggest evolution happens by
natural selection and survival of the fittest - organisms which are better adapted to their environment live healthier, longer lives, and reproduce these desirable characteristics to their offspring
what is sexual selection
a specific type of selection which relies on a organism’s ability to obtain or successfully copulate with a mate
strengths of the biological approach
- Good applicability because scanning research techniques are useful for investigating the functions of the brain: an extremely important organ in understanding our behaviour that would otherwise be unobservable.
- Good internal validity and scientific credibility because the experimental methods used (gathering empirical [i.e. observable] evidence) make this approach very scientific and replicable
weaknesses of the biological approach
- The approach is considered reductionist; complex behaviour, thoughts and emotions are all equally explained by low-level biological mechanisms such as biochemicals and nerve impulses.
- An extreme biological approach does not account for the wide base of evidence that points to the influence of our environment (e.g. culture and society).
