Biological Approach

• A01

  - Everything psychological (how we behave, think and feel) is at first biological. Therefore, psychologists should study the human body (nervous system and endocrine system) to understand human behaviour.​

  
  

  - The 'mind' is a product of the brain. ​

  
  

  - Genetic differences can explain individual differences in behaviour. ​

  
  

  - Genetic similarities can explain common/shared behaviours which have evolved in our species.
• What is the genotype?


  Genotype: genetic makeup/DNA 50% mother + 50% father
• Phenontype


  Phenotype: observable characteristics, features + traits including the way we behave - the phenotype is also affected by BOTH environmental + genetic factors
• Genotype and phenotype

  - In psychology a genotype only determines the potential for characteristics. ​

  
  

  - The observable characteristics of an individual (phenotype) depend on the interaction of genetic and environmental factors.​

  
  

  - Example - a genotype can genetically predispose someone to schizophrenia, but they will only actually develop schizophrenia if they are exposed to environmental factors as well. (phenotype)
• - Methods of investigating the genetic basis of human behaviour: 'Twin studies

  - Twin Studies: Psychologists are interested in studying twins in order to investigate the genetic basis of behaviour: MZ (monozygotic) 100% genetically identical DZ (dizygotic) genetically non-identical 50%

  Concordance rate: refers to the extent to which lots of pairs of twins share similar traits/characteristics e.g., out of 100 twins, where one of them is a smoker, if 35 of their win pairs are also smokers, we would say this is a concordance rate of 35

  
  

  - If a characteristic/trait is totally genetic, it would be a 100% concordance rate in MZ twins and a 50% in DZ twins, correlating with the amount of shared genetic material. E.g., the concordance rate for schizophrenia is 48% in MZ + 17% in DZ (however these could be explained by nurture alone)
• Concordance

  Concordance: refers to the extent to which a pair of twins share similar traits or characteristics e.g., if one twin is a smoker the other is also a smoker
• Methods of investigating the genetic basis of human behaviour:

  Family Studies: Concordance rates are also used to measure the rate of similarly between different family members

  
  

  Adoption studies: these studies involve comparing a trait/characteristic between adopted 'children' and their biological/ adoptive parents - concordance rates are also used

  
  

  Selective Breeding:

  Involves selecting male + female animals for who demonstrate a particular trait (e.g., being good at solving mazes)

  Allowing them to breed + observing/measuring the behaviour in the offspring (However, there is still the issue of nature vs nurture)

  
  

  Evolution + Behaviour :Evolution: the changes in inherited characteristics in biological population over successive generations

  
  

  Natural Selection: Charles Darwin proposed that animals (including humans) with particular traits that provide them with an advantage are more likely to survive and reproduce thereby passing on their 'adaptive traits' to their offspring
• Methods of studying the brain:

  The biological approach draws on concepts from the hard sciences and research tends to be highly scientific in nature.​

  
  

  -The most common methods include laboratory experiments and observations.​

  
  

  -Objective brain scanning techniques are also used - fMRI and PET. ​

  
  

  -As well as twin and family studies and selective breeding.
• Strengths of the biological approach

  P- it is a scientific approach

  E- we can establish cause + effect relationships between biology and behaviour

  E- has established psychology as a credible science
• Weakness of Bio Approach

  P- It totally negates the idea of free-will, which is socially sensitive.

  E-This is because it offers deterministic explanations of human behaviour - the way we behave is determined by our biological makeup which we have no control over.

  E- Therefore, suggesting that we shouldn't be held responsible for the way we behave - criminals
• Weakness of Bio Approach

  P-It ignores the influence of environmental factors on human behave.

  E-This is because it is Reductionist - stating that all human behaviour can be explained through biological processes alone,

  E-this is dehumanising to present humans as 'biological machines. ​
• What does the diathesis-stress model suggest about criminal behavior?

  It results from genetic predisposition and triggers
• Useful real-life application

  P-studying the impact of biology

  and behaviour can lead to the development of treatments

  e.g., diet, surgery and drug treatments e.g for OCD and the brains role in it link to forms of drug therapy
• Reliability

  Measurements are objective

  Machinery such as PET scans and EEG's have no vested interesting the outcome= no researcher bias

  The use of complex machinery allows for accurate and precise measurements
• Effects of brain physiology and neurochemistry:

  Interactions between regions of the brain help to control different functions, which biological psychologists assume to be significant in determining our actions.

  The occipital lobe is involved heavily in processing sight, along with the frontal lobe, which is thought to be involved in control and attention.
• Effects of brain physiology and neurochemistry:


  Electrical impulses are signals that travel through nerves to transmit information around the brain to/from the body via our nervous system

  Impulses are transmitted between neurons (nerves) at synapses, junctions where neurotransmitters are released that inhibit or excite other neurons to achieve different responses.
• Neurochemical imbalances: 


  often associated with abnormal behaviour – for instance, evidence suggests that imbalances of dopamine (a neurochemical linked with the brain’s natural ‘pleasure’ system) are associated with mood disorders such as depression.
• The Endocrine System:

  The endocrine system is a slower-acting communication system that regulates the circulation of hormones, released by glands into the bloodstream.

  For example, cortisol and adrenaline are key hormones that facilitate the fight or flight response, a key evolutionary survival mechanism whereby the body primes itself for imminent danger (e.g. increasing heart rate, initiating sweating to cool down, dilation of pupils, sharpened sense of hearing).
• Mednick Et al:

  • 14 427 Danish adopted children were analysed according to concordance. 
  • The concordance rates of criminality were compared between:
  • The adopted children and their adopted parents. 
  • The adopted children and their biological parents
• Results:

  • 13.5% of adopted children had a criminal conviction with biological or adoptive parents with no criminal convictions. 
  • 14.7% of adopted children had a conviction with at least one adoptive parent who had a criminal conviction. 
  • 20% of adopted children had a conviction with at least one biological parent who had a criminal conviction. 
  • 24.5% of adopted children had a conviction rate with at least one biological parent and one adoptive parent with a criminal conviction.
• Conclusion and Strengths:

  • There is a genetic link of criminality. 
  • However, overall, the concordance rates are low, therefore, there is likely to be other factors that lead to criminality.
  • Adoption studies are important in the nature vs. nurture debate as they can separate out the genetic and environmental influences. Therefore, this is a powerful study. 
  • The sample size was very large, increasing the validity of the results.
• Weakness

  • However the study only looked at criminal convictions, not at crimes committed. This is a limitation of the study.
  • In other words, people could have committed crimes and not been convicted. This could cause different results.