The Biological Approach

• Genotype

  The particular set of genes that a person possesses.
• Phenotype

  The characteristics of an individual determined by both genes and the environment.
• What is the biological approach?

  The biological approach suggests that everything psychological is at first biological, and so to fully understand human behaviour, we must look to biological structures and processes within the body.
• Concordance rate

  The proportion of pairs of individuals that share an attribute.
• What are twin studies often used to investigate?

  Whether certain psychological characteristics have a genetic basis. If a characteristic is genetic then all identical twins (monozygotic) would be concordant, as they share 100% if the same genes. The same would not be true for dizygotic twins, who would show a lower concordance rate as they only share 50% of their genes.
• Why might identical twins be different?

  Despite having the same genes, the phenotype (the way the genes are expressed) is different, illustrating that much of human behaviour depends on an interaction between nature (inherited factors) and nurture (the environment).
• What is the theory of evolution?

  Different species have all evolved from simple life forms which lived on earth 3 billion years ago.

  Evolution occurs through natural selection - any genetically determined behaviour that enhances an individuals survival and reproduction will continue in future generations.
• What is a strength of the biological approach? (scientific methods).

  The biological approach uses scientific methods of investigation, using a range of precise and highly objective methods. These include scanning techniques, such as fMRIs and EEGs, which allow us 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.
• What is a strength of the biological approach? (real world application)

  The biological approach has real world application. Increased understanding of the effects of neurotransmitters is associated with the use of drug therapies such as SSRI's, which are 50% effective in treating depression. This is evidence that there is a biological element to exploring behaviour.
• What is a limitation of the biological approach? (biological determinism).

  The biological approach is determinist as it sees our behaviour as caused entirely by biological factors over which we have no control. This encourages people to not take responsibility for their actions and to blame their genetics. It also means that other elements that impact how a genotype is expressed (e.g. our social and cultural environment) are not considered, suggesting that the biological approach is an incomplete explanation of human behaviour - it is too simplistic.
• What is double bind theory? (criticism of the biological approach).

  Double-Bind Theory proposed by Bateson is a psychological explanation for schizophrenia. It suggests that when children are consistently provided with two or more conflicting messages, they develop a false perception of reality, suggesting that schizophrenia is caused by psychological factors, not biological ones.
• What is a criticism of the biological approach? (Natural selection).


  Critics of Darwin's work, such as Karl Popper, claim that it is not possible to falsify the theory of natural selection (a key criterion of science) as we cannot show evolution happening, we can only deduce it has taken place. However, others claim that the basic principles are supported by fossil records (e.g. showing dinosaurs changing into birds).