What are the key assumptions of the biological approach?
All behaviour can be explained in terms of biological structures and processes within the body. Biological psychologists are particularly interested in genetics and neural differences. In contrast, the cognitive approach sees mental processes of the mind as separate from the physical brain.
The neurochemical basis of behaviour
Neurochemistry refers to the action of chemicals in the brain. Much of our thoughts and actions rely on chemicals in the brain, thus imbalances here could cause mental issues or disorders e.g. under-production of the neurotransmitter serotonin; low levels may cause low moods and disorders such as OCD.
The genetic basis of behaviour
Psychological characteristics, such as intelligence, are inherited in the same way as height or eye colour. Researchers use family, twin and adoption studies to assess the genetic basis of a disorder/behaviour. This can be achieved by analysing concordance rates; the extent to which twins share the same characteristic. If a characteristic is genetic we would expect all identical twins to be concordant.
Genotype and phenotype
A person's genotype is their particular set of genes, and their phenotype is the expression of their genes through physical, behavioural and psychological characteristics. Despite having the same genes, the phenotype of identical twins are different due to environmental factors and nature.PKU is a rare genetic disorder that can be prevented by a restricted diet if detected early enough. If not, it can cause severe learning difficulties.
Evolution and behaviour
The evolution of human behaviour develops in the same way as physical characteristics. Any genetically determined behaviour that enhances an individual's survival and reproduction will continue in future generations due to natural selection.
