AO1 - The Biological Approach

• Assumptions:

  • All human behaviour is at first biological, the mind lives in the brain
  • Physical factors such as our hormones, neuroanatomy, nervous system and the inheritance of genes can all explain our behaviour
  • An individual's genotype and phenotype will determine how we behave
• Genotype: Specific set of genes than an individual has inherited from their biological parents and is unique to them. Genotypes can give a genetic predisposition to disorders
• Phenotype: Product of what happens when the genotype interacts with the environment. This is how our genes are expressed through physical, behaviour and psychological characteristics, they are observable traits or behaviours shown by an individual
• The first feature of the biological approach is the influence of genes on behaviour
• Influence of genes:

  • Behavioural characteristics such as intelligence, personality and mental illness are genetically inherited the same way as physical characteristics such as eye colour - behaviours run in families
  • Genetic explanation argues that OCD is due to the inheritance of one or many maladaptive genes, e.g. SERT
  • Closer the genetic link to someone with OCD, the greater the risk of inheriting it. The genetic probability of sharing a behaviour is measured by concordance rates
  • Higher the concordance rate, the stronger the evidence for a genetic basis of behaviour
• The second feature of the biological approach is the influence of biological structures on behaviour
• Influence of biological structures:

  • A biological structure is an organ, such as the brain, or a system, such as the nervous system
  • The brain is a biological structure that can influence behaviour - abnormalities in size, shape or function in certain areas of the brain can lead to certain behaviours
  • For example, enlarged ventricles in the brain increases a person's vulnerability to schizophrenia
• The third feature of the biological approach is the influence of neurochemistry on behaviour
• Influence of neurochemistry:

  • A neurotransmitter is a chemical messenger in the brain that passes information from one synapse to the other to produce behaviour/emotion
  • There are a range of neurotransmitters in the brain that communicate these messages, an imbalance of neurotransmitters can cause abnormal behaviour
  • An imbalance of dopamine has been linked to the development of schizophrenia
• The fourth feature of the biological approach is evolution and behaviour
• Evolution and behaviour:

  • Charles Darwin created the theory of natural selection - any genetically determined behaviour that increases an individuals survival and reproduction rates will be passed onto future generations
  • This process takes place naturally, it happens because the individual who possessed certain beneficial traits will have increased chance of survival and therefore will be able to pass on the beneficial traits to their offspring
  • For example, aggression - would have been advantageous for survival and increasing reproduction, one third of men have the 'warrior' gene: MAOA