The biological approach

Assumptions

• A perspective that emphasises the importance of physical processes in the body such as genetic inheritance and neural function.

• All thoughts, feelings, and behaviour ultimately have a physical basis.

• This is in contrast to, say, the cognitive approach that sees mental processes of the mind as being separate from the physical brain.

The neurochemical basis of behaviour

• Relating to chemicals in the brain that regulates biological and psychological functioning. This occurs using neurotransmitters.

• An imbalance of, for example, dopamine and serotonin have been implicated as possible causes of mental disorders. Low levels of serotonin in OCD and overproduction of dopamine in schizophrenia.

The genetic basis of behaviour

• Psychological characteristics, such as intelligence, are inherited in the same way as height or eye colour.

• Twin studies are used to investigate whether certain psychological characteristics have this. This is achieved by analysing concordance rates - the extent to which twins share this.

• We expect all monozygotic (identical) twins to be concordant (they share 100% of the same genes), whereas the same would not be true for non-identical (dizygotic) twins who share about 50% of the same genes - In both cases the environment is assumed to be constant.

Genotype

A person's actual genetic make-up.

Phenotype

The way that genes are expressed through physical, behavioural, and psychological characteristics - Despite having the same genes, the way identical twins' genes are expressed is different.

Evolution and behaviour

- Charles Darwin proposed the theory of natural selection. The main principle of this theory is that any genetically determined behaviour that enhances an individual's survival (and reproduction) will continue in further generations. The possessor of such traits is more likely to survive, reproduce, and pass them on. If the individual survives but does not reproduce, the traits do not remain in the gene pool for successive generations.

Strengths

• The approach has real-life application. Increased understanding of neurochemical processes in the brain is associated with the use of psychoactive drugs to treat serious mental disorders. E.g. The biological approach has promoted the treatment of clinical depression using antidepressant drugs that increase levels of serotonin at synapses in the brain, such drugs have been associated with the reduction of depressive symptoms. This means that people with depression may be better able to manage their condition and live their lives in the community, rather than remain in hospital.

• Although antidepressant drugs are successful for many patients, they do not work for everyone. A recent study compared different antidepressant drugs and found wide variations in their effectiveness. Although most of the drugs were more effective than placebos, the researchers concluded that the effects of antidepressants were ‘modest’. This challenges the value of the biological approach because it suggests that brain chemistry alone may not account for all case of, for example, depression.

• The approach uses scientific methods of investigation. In order to investigate the genetic and biological basis of behaviour, the biological approach makes use of a range of precise and highly objective methods. With advances in technology, such as fMRIs, it is possible to accurately measure physiological and neural processes in ways that are not open to bias. This means that much of the biological approach is based on objective and reliable data.

Limitations

• The approach is deterministic. The approach sees human behaviour as governed by internal, genetic causes over which we have no control. However, we have already seen that way in which an individual's genotype is expressed is heavily influenced by the environment. Not even identical twins who share the same genes look the same and think the same. Also, a purely genetic argument becomes problematic when we consider things such as crime (a criminal could excuse their actions claiming they committed crimes due to genes). This suggests that the biological view is often too simplistic and ignores the mediating effects of the environment.