Biological Approach

• Genes

  Components of chromosomes that contain DNA that codes the physical features of an organism. Transmitted from parent to offspring
• Biological structure

  An arrangement or organisation of parts to form an organ, system or living thing
• Neurochemistry

  The regulation of psychological functioning via chemicals in the brain
• Genotype

  The particular set of genes that a person possesses - a person’s genetic make-up:

  Expression of a genotype is inevitably influenced by environmental factors e.g. dying hair would change the way that identical twins look in relation to each other.
• Phenotype

  The way that genes are expressed through physical, behavioural and psychological characteristics = environment an affect the phenotyp
• Evolution

  The change in inherited characteristics in a biological population over successive generations
• Genetic basis for behaviour

  Psychological characteristics are inherited the same way height or eye colour are. Twin studies are used to investigate whether certain psychological characteristics have a genetic basis.
• Finding a genetic basis is determined through concordance rates - the extent to which twins share the same characteristic
• If a characteristic i.e schizophrenia is genetic, we would expect all identical (monozygotic) twins to be concordant [sharing 100% of the same genes]. For non-identical twins (dizygotic), it would be a 50% share of genes. Environment in both cases are assumed to be constant
• Biological psychologist acception - that much of human behaviour depends upon an interaction between inherited factors (nature) and the environment (nurture)
• PKU is an example of genotype since it is a rare genetic disease

  If left untreated, it can cause severe learning difficulties - the phenotype
• The Theory of Natural Selection, Charles Darwin

  Main principle - Any genetically determined behaviour that enhances an individuals’s survival (and reproduction) will continue in future generations ie. being naturally selected - similar to farmers selecting animals with the desirable characteristics > high milk yielding cows bred so whole stock becomes progressively better

  In nature, naturally occurs as some traits give the possessor certain advantages - the possessor is more likely to survive, reproduce and pass on thes trais