Outline and evaluate the biological approach

What are the 4 main assumptions of the biological approach?

• Everything psychological is at first biological - any behaviour has a biological basis and originates from biological structures.

• Inheritance - behaviour can be inherited and is determined by our genetics.

• Influence of the environment - our inherited genetic make-up is heavily influenced by the environment, as seen in the relationship between genotype and phenotype.

• Human behaviour has evolved - human behaviour has evolved over generations due to natural selection for survival.

What type of studies are used in the biological approach?

Twin studies

What is the difference between monozygotic twins (MZ) and dizygotic twins (DZ) ?

MZ share 100% of DNA

DZ share 50% of DNA

What are concordance rates?

The extent to which both twins share the same characteristic

What does a high concordance rate suggest?

In MZ twins, if one twin demonstrates a behaviour the other is much more likely to develop it compared to DZ twins.

High concordance rates suggest a string genetic component as MZ twins share 100% of the same genes.

What is a genotype?

A person's genetic make up which occurs at conception.  

Provides a genetic code that predisposes an individual as to how they will develop.

What is a phenotype?

The observable characteristics shown by a person

Can either be an expression of their genotype on its own or as a result of a combined effect between their genotype and an environmental factor

AO3: Reliance on MZ and DZ studies (Limitation)

High concordance rates may be explained by shared environmental conditions rather than shared genetic similarity.

It is likely that MZ twins are treated more similarly than DZ twins as they look alike and so may often be treated as the "same person"

Argued to have difficulty separating nature and nurture influences

AO3: Scientific methods (Strength)

A key strength of the biological approach is that it is scientific.

It uses the scientific method, particularly the experimental method as its main investigation method.

They are carried out in highly controlled environments, so researcher can replicate. The fact they can be reproduced adds to the validity of the original findings and show reliability. The sophisticated technology increases overall precision to the approach.

These techniques have added scientific credibility to the approach and enables us to provide predictions on behaviour which we can test and provide.

AO3: Real life application (Strength)

It has many positive real life applications to biological approach, demonstrating strong explanatory powers.

We can develop effective strategies for managing behaviour in the real world, due to clear predictions, such as neurotransmitters on behaviour.

For example, the research done into circadian rhythms has lead to improvements in working conditions of shift-workers or neurochemical imbalances in depression have lead to development of SSRI's.

This demonstrates key value in adopting biological approaches and suggests one approach has good explanatory powers- if it can be used in real life, it must be true.

AO3: Reductionism (Limitation)

The biological approach is reductionist.

It is criticised for its belief that complex behaviours can be broken down into the action of genes, neurochemicals and hormones.

For example, many mental disorder explanations are reductionist as genes/ neurochemical imbalances are believed to be the main cause.

We can’t fully understand behaviour without also taking account of other factors that influence it, including cognitive, emotional and cultural factors, all which have significant influences on behaviour.