biological

• Neurochemical Basis

  • Chemicals in the brain have an impact on our behaviour
  • Our thoughts and behaviours rely on chemical transmission, which occurs using neurotransmitters
  • They inhibit or excite other neurons to achieve different responses
  • Neurochemical imbalances in the brain are often associated with abnormal behaviour
  • For example, low levels of the neurotransmitter serotonin is associated with OCD and overproduction of dopamine is associated with schizophrenia
• Genetic Basis

  • Behavioural and psychological characteristics are inherited in the same way as height or eye colour
  • Twin studies are used to determine the likelihood that certain traits have a genetic basis
  • They compare the concordance rate between pairs of twins to see the extent to which both twins share the same characteristics
• Evolution & Behaviour

  • Darwin proposed the theory of natural selection, that any genetically determined behaviour that enhances an individual's survival will continue in future generations
  • This known as the theory of natural selection
• Genotype & Phenotype

  • A person's genotype is their actual genetic make-up
  • The phenotype is the way that genes are expressed through physical, behavioural and psychological characteristics
  • Despite having the same genes, the way identical twins' genes are expressed (the phenotype ) is different
  • Shows that human behaviour depends on an interaction between inherited factors (nature ) and environment (nurture)