Biological approach

• Key assumptions:

  • Genes are most important in helping us to understand behaviour
  • Behaviour can be passed/ inherited
  • Interested in studying twins to try and find evidence for genetic explanations for behaviour
  • Role of brain chemistry and hormones
  • Evolution - as an explanation
• The influence of genes on behaviour:

  • Heredity is the passing of genes from one generation to the next through genes
  • Twin studies were used to determine the likelihood that certain traits have a genetic basis by comparing the concordance rates between pairs of twins
  • If identical (MZ) twins are found to have higher concordance rates than non-identical (DZ) twins, then this would suggest a genetic basis.
  • MZ- share 100% genes
  • DZ- share about 50%
• The influence of genes on behaviour:

  • Genotype- person's actual genetic make-up
  • Genotype- inevitably influenced by environmental factors
  • Phenotype- the way genes are expressed through physical, behavioural and psychological characteristics
  • Many biological psychologists would accept, that much of human behaviour depends upon an interaction between inherited factors (nature) and the environment (nurture).
• Neurons and the nervous system :

  • Nervous system= CNS + PNS
  • CNS= brain + spinal cord
  • PNS= somatic and autonomic NS
  • NS carries info from one part of the body to another using individual cells (neurons)
  • Neurons transmit nerve impulses in the form of electrical signals
  • Many aspects of behaviour are under neuronal control (breathing, eating)
• The Brain:

  • Largest part is the cerebrum= 85% of the brains total mass
  • Outer surface of the cerebrum is the cerebral cortex= responsible for many of the 'high-order' functions like thoughts and language
  • Cerebrum= two halves (hemispheres) divided into four different parts: Frontal lobe- social & emotional functions, Temporal lobe- involved in movement & sensory processes, Parietal lobe- processes info about temp, taste, Occipital lobe- responsible for vision
• Neurotransmitters:

  • Chemical messengers that allow an electrical impulse to travel from the nerve ending of one neuron to another
  • Excitatory- trigger the receiving neuron to send a impulse- may increase our motivation and or drive
  • Inhibitory- stop if from doing so, calm the brain and balance mood
• Hormones:

  • Produced by the endocrine glands and are secreted directly into the bloodstream and exert their influence by stimulating receptors.
  • Cause physiological reaction in the cell altering activity
  • E.G. Carre et al (2006) found an increase in testosterone whenever a Canadian ice hockey team played in their home stadium suggesting the hormone energised the players to defend their home territory.
• Evolution and behaviour:

  • In the 19th Century, Charles Darwin proposed the theory of natural selection, which suggests that any genetically determined behaviour that enhances an individuals survival will continue in future generation. Explains why certain traits are adaptive
• AO3:

  • Limitation- reductionism refers to being able to break down complex human behaviour into small component parts. Whilst this can be useful in understanding the causes of certain behaviours it may pose problems. Only take into account biological factors and not childhood experiences or the environment.
• AO3:

  • Strength- Uses the scientific method particularly in the experimental method, as it's main method of investigation. E.G experiments take place in highly controlled environments and often use sophisticated imaging and recording techniques. We get accurate results that can help strengthen the fact that biological factors are the reason for certain behaviours.
• AO3:

  • Strength- the ability to make clear predictions is a + of this approach as it provides significant real-world applications. E.G. research into the role of neurochemical imbalance in depression has led to the development of drug treatments, which correct this imbalance and minimise depressive symptoms. Can help to produce medication to get a better handle on the mental disorder and also helping society to become more aware and helpful in understanding certain situations.