Biological Approach

• • Everything psychological is at first biological.
  • Psychologists should study biological structures and processes, nervous system and other biological systems, e.g. hormones, neurotransmitters.
  • The mind lives in the brain (in contrast to the cognitive approach sees mental processes of the mind as being separate from the physical brain).
• Neurochemistry

  Refers to the action of chemicals in the brain - Neurotransmitters transmit messages. An imbalance of neurotransmitters can be a cause of some mental disorders e.g. underproduction of serotonin in OCD.
• Genetic Basis of Behaviour

  Believe characteristics such as intelligence, are the product of inheritance (genes).
• Twin Studies

  There should be 100% concordance rates between MZ twins if a particular characteristic / trait is a purely genetic one. DZ twins will show lower concordance rates. Comparisons can be made between twins raised together and twins raised apart.
• Genotype And Phenotype

  The basic units of heredity are called genes. Genes function in pairs and the recombination of genes from parents to offspring provides the basis for genetic variability.
• Genotype

  A person’s genotype is their actual genetic make-up. Examples include eye colour, height, shoe size.
• Phenotype

  Phenotype is the way that genes are

  expressed through behavioural, physical and psychological characteristics. The phenotype is influenced by the genotype and factors including:

  • Epigenetic modifications – affect the way your genes work e.g. lifestyle – such as smoking. Does NOT change DNA sequence.

  • Environmental and lifestyle factors.
• Evolution

  The changes in inherited characteristics in a biological population over successive generations. Darwin emphasised two main concepts in evolutionary theory:

  •natural selection

  •sexual selection
• Natural Selection

  Animals 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. Attachment behaviours in newborns promote survival and are therefore adaptive and naturally selected.