Biological Approach

• Assumptions:

  the biological approach suggests that all behaviour is the result of biological structures and processes. There are 4 features;

  • genes
  • biological structures
  • evolution
  • neurochemistry
• The influence of genes on behaviour:

  • children inherit their genes from their parents (passed on)
  • they carry information/instructions that code for physical features (eye colour/height) as well as psychological features (personality/intelligence)
• Genotypes and phenotypes:

  • your genotype is your genetic makeup
  • phenotypes are the observable traits that are due to the combined effects of genes and the environment
  • an example of this is that someone may have the specific genes to develop depression (variations of the SERT gene). This is your genotype. The gene will only be expressed and result in depression if you experience a traumatic life event. This is your phenotype
• Twin studies:

  in order to identify whether behaviour is a result of a genetic disposition or the environment in which we are raised we can use twin studies;

  • monozygotic (MZ) twins are identical twins. They share 100% of their genes
  • dizygotic (DZ) twins are non-identical twins. They share roughly 50% of their genes on average
• Twin studies:

  • twin studies look at concordance rates in twins, This is the percentage of the twins who share a certain behaviour with their twin. Therefore, this explains the likelihood of one twin having a behaviour and the other twin also having the behaviour
  • both twins share an environment, so if there's a difference in the concordance rate between MZ and DZ then this will tell us how much of their behaviour is influenced by genes
• Assessing the influence of genes - twin studies:

  • MZ concordance is higher than DZ concordance - genes must play a role in this behaviour as the identical twins are more similar than the non-identical twins
  • MZ concordance is not 100% - the environment must play some part as you would expect identical twins with identical genes to have the same behaviour
  • no difference between MZ and DZ concordance - little to no genetic influence on this behaviour as MZ and DZ twins share differing levels of genes
• Examples of concordance rates:

  a twin study compares concordance rates for OCD in MZ and DZ twins

  • MZ concordance = 87% (for every 100 with OCD, 87 of their MZ twin has OCD)
  • DZ concordance = 47% (for every 100 with OCD, 47 of their DZ twin has OCD)

  as MZ concordance is higher, it suggests their genetic similarity is the thing that is causing the OCD. However as it is not 100%, it suggest that there must be other environmental factors that cause OCD (such as family life or stress)
• Biological structures:

  biological structures that influence behaviour include the following;

  • the nervous system influences our fight or flight reaction to danger
  • structures within the brain influence our behaviour

  the brain is in charge of decision-making, attention and higher-order thinking. It is divided into different areas which all have different roles in determining our behaviour. For example, the Broca's area is responsible for speech production
• Example of influence of biological structures on behaviour:

  • brain-scanning research has shown people who suffer from OCD have higher activity in an area of the brain known as the orbitofrontal cortex (OFC), which is located in the frontal lobe
  • this suggests that activity in this area is responsible for the obsessive thoughts seen in OCD
• Evolution:

  evolutionary psychologists believe all human behaviour is a result of genes being passed down over billions of years. They suggest all behaviour has been caused by the evolutionary pressures to survive and reproduce

  • millions of years ago, behaviours that helped our ancestors to survive/reproduce were passed on via genes
  • we say that these behaviours are adaptive
• Evolution:

  • behaviours that did not help survival or reproduction meant that this person was less likely to pass on their genes. This is called the theory of natural selection
  • traits that aid survival/reproduction are seen as attractive when deciding a partner, meaning that these people are more likely to find a mate and then pass on their genes to the next generation. This is known as sexual selection
• Example of evolution influencing behaviour:

  • evolutionary psychology can explain OCD as it suggest that groups which have someone who is highly vigilant and obsessive about safety and checking that there are not any threats would be more likely to survive as it means they are less likely to be attacked
• Neurochemistry:

  neurochemistry is the study of chemicals that influence the brain. It can be split into the role of;

  • hormones
  • neurotransmitters
• Hormones:

  • these are chemical messengers that travel through the bloodstream
  • they are released by glands
• Examples of hormones influencing behaviour:

  • adrenaline is a hormone which is released by the adrenal gland during the fight or flight response. It leads to bodily changes (increased breathing/heart rate and the slowing down of digestion) so that we can either fight the threat of escape from the threat
  • the role of testosterone on aggressive behaviour. Dobbs (1995) measured the testosterone levels from the salvia of 692 adult male prisoners. There were higher levels in violent offenders and rapists than in non-violent offenders (burglars and thieves)
• Neurotransmitters:

  • neurotransmitters are chemical messengers that travel via the nervous system
  • they travel from neuron to neuron via a process known as synaptic transmission
• Examples of neurotransmitters influencing behaviour:

  • the neurotransmitter dopamine has been found to be significantly higher in people who suffer from schizophrenia, as they have more receptors that are receptive to this neurotransmitter
  • this relays sensory information and it has been suggested that this can lead to a sensory overload, resulting in hallucinations and delusions
• Evaluation of the biological approach:

  S - supporting evidence from twin studies

  W - the approach ignores the role of the environment

  S - there are positive practical applications of the biological approach in treating mental health disorders using drugs

  W - determinism - biological determinism and lack of free will
• Supporting evidence from twin studies (identify):

  • there is supporting evidence for the influence of genes on behaviour from twin studies, such as Coccaro's twin study looking at aggressive behaviour
• Supporting evidence from twin studies (explain):

  • Coccaro et al (1997) compared monozygotic and dizygotic twin pairs. They were examined for the concordance of criminal behaviour for both twins
  • the MZ twin pairs were found to have 50% concordance, whereas DZ was only 19%
  • this research supports the role of genetics in aggression, as the twins that were genetically identical (100% of the same genes) were more likely to display criminal behaviour that twins that only shared 50% of the same genes
• Supporting evidence from twin studies (conclusion):

  • this adds to the validity of the biological approach as it provides empirical evidence in support of the influence of genes on behaviour
  • as the MZ twin pairs share more of their genetic makeup and they were more aggressive than the DZ twin pairs, this suggests that genes do play an important part in explaining human behaviour
• Supporting evidence from twin studies (counter-argument):

  • this concept is reductionist as it doesn't take into account that the twins may have had slightly different upbringings which may have a bigger influence on their behaviour than their genes
• The approach ignores the role of the environment (identify):

  • one limitation of the biological approach is that it ignores the role of the environment in explaining human behaviour
• The approach ignores the role of the environment (explain):

  • alternative theories, such as SLT would suggest that instead of behaviour being down to biological factors (nature), human behaviour can be explained in terms of environmental exposure (nurture)
  • for example, aggression with SLT believes that this developed though the observation and imitation of aggressive role models, providing they are vicariously reinforced, rather than being a result of hormones like testosterone
• The approach ignores the role of the environment (conclusion):

  • this questions the validity of the biological approach because it suggests it ignores the role of the environment, therefore it may be best to look at behaviour from a more holistic point of view and take into account more environmental factors, like learning
  • therefore, an interactionist approach to explaining behaviour such as the diathesis-stress model may be more appropriate
• Practical applications - antipsychotics to treat schizophrenia (identify):

  • a strength of the biological approach is that it has led to effective therapies, such as antipsychotics used to treat schizophrenia
• Practical applications - antipsychotics to treat schizophrenia (explain):

  • if schizophrenia is understood as a consequence of excess dopamine then drugs can be developed to block the transmission of this dopamine and stop people experiencing auditory hallucinations, therefore improving people's lives
• Practical applications - antipsychotics to treat schizophrenia (conclusion):

  • this adds to the ecological validity of the biological approach as its principles have helped many people with their mental health and demonstrates that our neurochemistry does have an influence on our behaviour
  • this also benefits the economy
• Determinism - biological determinism and a lack of free will (identify):

  • the main issue with the biological approach is that it is considered deterministic and does not allow for the role of free will
• Determinism - biological determinism and lack of free will (explain):

  • biological determinism occurs when people’s behaviour is seen as a product of their biological makeup and not their own free will
  • on one hand this a strength because it means we can establish a clear cause and effect relationship between our genes and neurochemistry (to predict future behaviours)
  • this means the approach is seen as scientific and controlled to understanding human behaviour
• Determinism - biological determinism and lack of free will (explain):

  • on the other hand, this is problematic because it removes free will from people and they may believe that their future is predetermined and they have no control over it
  • for instance, someone who has aggressive genes in their family may think that they are destined to inherit this gene and therefore will act aggressively (which could be a self-fulfilling prophecy)
• Determinism - biological determinism and lack of free will (conclusion):

  • this could be seen as potentially socially sensitive as it may end up with criminals being absolved of their crimes if they are seen as less responsible for them due to their inherited characteristics like genes
  • this may upset/offend the victims/the victims family who feel the removal of the blame minimises the significance of their trauma and could excuse/normalise aggression in others