Outline and Evaluate the Biological Approach (16 marks)
The biological approach suggests that everything psychological is at first biological, so to
fully understand human behaviour, we must look to biological structures and processes within
the body, such as genes, neurochemistry, and the nervous system. From a biological
perspective, the mind lives in the brain, which means all thoughts, feelings, and behaviour
ultimately have a physical basis. This is in contrast to the cognitive approach, for example,
which sees mental processes of the mind as being separate from the physical brain.
Evolution is an important part of the biological approach. Charles Darwin proposed the
theory of natural selection, which states that individuals who have physical and behavioural
characteristics that enable them to survive and reproduce pass them on to the next generation.
Through this process of evolution by natural selection, successive generations become better
adapted to their environment.
Behaviour geneticists study whether behavioural characteristics, such as intelligence,
personality, mental disorder etc. are inherited in the same way as physical characteristics such
as height and eye colour. There is evidence from twin studies that supports that some people
are vulnerable to OCD as a result of their genetic make-up. Nestadt et al reviewed previous
twin studies and found that 68% of identical twins shared OCD as opposed to 31% of non-
identical twins, which strongly suggests a genetic influence on OCD.
A person’s genotype is their actual genetic make-up, whereas phenotype is the way that genes
are expressed through physical, behavioural, and psychological factors. For example,
identical adult twins usually look slightly different because one has exercised more, or one
has dyed their hair and so on. So, despite having the same genes, the way identical twins’
genes are expressed is different. This illustrates what many biological psychologists would
accept, that much of human behaviour depends upon an interaction between inherited factors
and the environment.
A strength of the biological approach is that it makes use of a range of precise and highly
scientific methods. These include scanning techniques such as fMRI and EEGs, family and
twin studies, and drug trials. With advances in technology, it becomes possible to accurately
measure biological and neural processes in ways that are not open to bias, which means the
biological approach is based on reliable data. For example, Senczyszyn (2023) found, in a
randomized controlled study, that transcranial magnetic stimulation (TMS) of the dorsolateral
prefrontal cortex in older adults significantly improved working memory. The non-invasive
advantages of TMS may have practical applications to all groups as the understanding of
decision-making processes and their links to memory and cognitive processes in general
improve. This shows that the biological approach has useful real-life practical applications.
Moreover, increased understanding of biochemical processes in the brain has led to the
development of psychoactive drugs that treat serious mental illnesses, such as OCD. There is