Biological approach

• The biological approach is a perspective that emphasises the importance of physical processes in the body such as genetic inheritance and neural function.
• Influence of genes on behaviour:

  -genes are inherited from our parents.

  -genes carry the instructions for a particular characteristics

  -our characteristics are inherited through our parents e.g certain disabilities or eye colours.  
• Genotype is the genetic makeup of an individual and it's written into their DNA. These genetic details are passed from generation to generation to generation.
• Phenotype is the observable characteristics of an individual. These are the ways in which the genes are expressed through physical appearance, behaviour psychological characteristics.
• The genetic basis of behaviour:

  -genetics can be used to study behavioural characteristics.

  -twin studies are used to determine the likelihood that certain traits have a genetic basis, they compare the concordance rates between pairs of twins to see the extent of which both twins share the same characteristics.
• Concordance rate = percentage of identical twin pairs who show the characteristic being studied.
• Monozygotic twins are genetically identical and share 100% of their genes.
• Dizygotic twins are identical twins that develop from two separate fertilised eggs. They share 50% of each others genes.
• The influence of biological structures on behaviours:

  -cerebrum, making up 85% of the total mass of the brain.

  -the cerebrum is divided into two hemispheres and each hemisphere is further divided into four different lobes.  
• Influence of biochemicals on behaviour:

  1.Hormones

  A signal from the brain tells the endocrine glands to secrete hormones directly into the bloodstream. They travel to target cells where they stimulate receptors and cause a physiological reaction in the cell.
• Influence of biochemicals on behaviour:

  2.Neurotransmitters.

  When a nerve impulse reaches the end of a neuron, a chemical called a neurotransmitter is released. It travels from one neuron to the next across a synapse.
• There are 4 main assumptions:

  -genes

  -brain damage

  -biochemistry

  -evolution
• Evolution and behaviour:

  -Charles Darwin proposed the theory of natural selection.

  -Certain physical and psychological traits have been passed down from one generation to another due to their advantages in survival and reproduction.

  SURVIVAL OF THE FITTEST
• Evolution is the GRADUAL change within a species over SEVERAL GENERATIONS in response to environmental pressures.
• Evaluation of the Biological approach:

  -Scientific method – the approach investigates behaviour through lab experiments. Lab experiments have high levels of control thus the experiment can be replicated and so the experiment has high internal validity.

  -Application – the biological approach has useful applications in the real world such as research into the roles of hormones affecting behaviour such as aggression and depression, allowing for the development of drug treatments to help with these conditions.
• Evaluation of the Biological approach:

  -Reductionist – we can’t explain behaviour just by looking at one factor (the biological factor), you must consider other factors such as social and cognitive.

  -Deterministic – the biological approach highlights that behaviour is deterministic and governed by internal biological causes that we can’t control. Thus, criminals behaviour is explained by a ‘criminal gene’ which can lead to people not being held accountable for their own actions which would cause havoc in the legal system.