Biological Approach

• our behaviour has adapted and changed over time through natural selection, which is where profitable behaviours are selected in mates and therefore reproduced
• biological psychologists propose that characteristics are passed form one generation to the next through the individuals genotype
• genotype refers to the genes that an individual possesses, these can by physical or psychological
• phenotype refers to the observable traits shown by an individual that are due to the combined effect of genes and environment
• twin studies involve comparing the likelihood of behaviour/disorder occuring in identical MZ twins and nonidentical DZ twins

  if MZ twins show a higher concordance rate than DZ twins, there is argued to be a genetic component to the behaviour/disorder since the environment of the twins are assumed to be same, only the genetics are the different
• adoption studies involve investigating whether a childs behaviour/disorder has occurred from their biological parent or from the adoptive parent

  if a childs behaviour is more similar to the biological parent, it is assumed to be inherited
• a strength of the proposal that behaviour has a genetic basis is that it has received supporting evidence, for example, twin studies have found a higher concordance rate in MZ twins than in DZ twins for a variety of disorders such as OCD and schizophrenia

  this is a strength since the higher concordance rates of the MZ twins can be explained by them sharing more genes
• a limitation of the proposal that behaviour has a genetic basis is that the supporting evidence may be at risk of cofounding variables since it has been suggested that MZ twins are more likely to be treated the same and share similar experiences since they look alike and are of the same sex

  this is a limitation because twin study evidence showing higher concordance rate between MZ twins may be due to similar environmental experiences rather than genetics
• findings that adopted children display similar behaviour to their parents may be because they spent a lot of their early childhood with their parents and so observed and imitated this behaviour

  this is a limitation since it suggests their behaviour is due to environmental experiences rather than genetics
• the brain is part of the central nervous system and compromises of four lobes: the frontal lobe, parietal lobe, occipital lobe and temporal lobe
• the frontal lobe deals with decision making and voluntary motor movement, it also contains brocas area which is responsible for speech production
• the temporal lobe deals with function such as auditory perception and contains wernicke's area which is responsible for speech comprehension
• the parietal lobe deals with functions such as processing touch sensations
• the occipital lobe deals with functions such as visual perception
• neurons communicate with one another through chemicals called neurotransmitters, biological psychologists propose that neurotransmitter levels can affect behaviour
• serotonin is a mood regulating neurotransmitter, too little of it has been linked to depression
• dopamine is a neurotransmitter that has been linked with reward seeking behaviour and movement, too much of it has been linked with the compulsive behaviour of OCD
• the endocrine system compromises of glands that secrete hormones into the blood stream
• the most important gland is the pituitary gland which is located in brain, it is sometimes called the master gland because it instructs other glands to secrete hormones when necessary
• glands secrete chemicals called hormones biological psychologists propose that hormones levels can affect behaviour
• high testosterone, dominantly secreted by the testes in males, has been linked to aggressive behaviour
• adrenaline is associated with the fight or flight behaviours
• melatonin is associated with tiredness and sleep
• a strength of the proposal that biological structures affect human behaviour is that it has received supporting evidence, for example, post mortem studies found that patients who had trouble speaking often damage to the broca's area while patients who had trouble understanding speech often had damage to the wernicke's area

  this is a strength since it suggests that different brain regions are responsible for different functions
• a limitation of the proposal that biological structures influence behaviour is that supporting evidence from post mortems can be confounded

  this is because the brain naturally decays after death meaning that damage observed may be unrelated to the patient's abnormal behaviour
• a strength of the proposal that biological structures influence behaviour is that it has received supporting evidence from brain scanning studies

  for example, studies have shown increased activity in brocas area during a speech production task and increased activity in wernicke's area during a speech comprehension task

  this is a strength because it shows that different brain regions are responsible for different functions
• a strength of the proposal that neurochemistry influences behaviour is that it has received supporting evidence

  for example research into SSRIs as a drug therapy for depression has found that they are effective at reducing depressive symptoms

  this is a strength since it shows how increases serotonin can lead to emotional and in turn behavioural changes
• a strength of the proposal that neurochemistry affects behaviour is that it has received supporting evidence

  animal studies have found that administering testosterone to rats causes them to display more aggressive behaviours

  this is a strength since it shows how increased testosterone can affect behaviour
• a strength of the biological approach is that it proposes biological determinism, since it proposes that factors like genetics and neurochemistry can affect behaviour

  this is a strength since science relies on determinism in order to establish cause and effect, thus increasing the scientific status of the biological approach
• a limitation of the biological approach is that the assumptions are biologically reductionist

  for example, it proposes that abnormal dopamine activity is the cause of schizophrenia

  this is a limitation since schizophrenia is a complex disorder that has been found to have multiple biological and environmental triggers
• a strength of the biological approach is that it has received supporting evidence

  for example twin studies have found a higher concordance rate in MZ twins than in DZ twins for a variety of disorders including OCD and schizophrenia

  this is a strength of the genetic basis of behaviour because the higher concordance rate of MZ twins can be explained by them sharing more genes
• a limitation of the biological approach is that the evidence from twin studies is at risk of confounding variables since it has been suggested that MZ twins are more likely to be treated the same and share similar experiences than DZ twins because they look more alike and are the same sex
• a strength of the biological approach is that it has had practical applications

  based on biological theories proposing that depression is caused by a lack of serotonin, SSRIs have been developed to increase serotonin levels in the brain

  this is a strength because such drug therapies have been effective in treating disorders including depression