The biological approach: the influence of genes, biological structures and neurochemistry on behaviour. Genotype and phenotype, genetic basis of behaviour, evolution and behaviour.

Assumptions:

Biological approach suggests everything that is psychological was once biological, so yo fully understand human behaviour, we must look to biological structures within the body, such as genes, neurochemistry and the nervous system. An understanding of brain structure and functions can explain our thoughts and behaviour. From a biological perspective the mind lives in the brain, meaning that thoughts, feelings and behaviour ultimately have a physical basis. This is a direct contrast to the cognitive approach that sees the mind and brain as separate entities.

The genetic basis of behaviour:

Behaviour geneticists study whether behavioural characteristics, such as intelligence, personality, mental disorders etc., are inherited in the same way as physical characteristics, such as height and eye colour. Twin studies are used to determine the likelihood that certain traits have a genetic basis by comparing concordance rates between pairs of twins; that is the extent to which both twins share the same characteristic. If monozygotic twins show higher concordance rates than dizygotic twins – for musical ability, schizophrenia, love of comedy films for example, this would suggest a genetic basis. This is because monozygotic twins share 100% genes whilst dizygotic twins only share 50% of genes.

Genotype and Phenotype:

A person`s genotype is their actual genetic make-up, whereas phenotype is the way genes are expressed through physical, behavioural or psychological characteristics. The expression of a genotype is inevitably influenced by environmental factors – i.e. identical twins may look different as…