8.5 Idiographic & Nomothetic Approaches

What is the essence of this debate?

• This debate weighs up the relative merits of studying people in general (nomothetic) or the individual (idiographic)
• A nomothetic approach seeks to apply general laws of behaviour
• An idiographic approach seeks to understand the subjective experience of the individual

Should psychology concern itself with the uniqueness of the individual or with a generalised understanding of behaviour?

The nomothetic approach

• The aim of nomothetic research is to investigate groups of people in order to be able to generalise findings 
• Nomothetic research tends to favour scientific methods such as lab experiments which involve high levels of control 
• Nomothetic research aims to use large sample sizes so as to generate robust quantitative data which is able to withstand statistical analysis
• Research such as Eysenck’s personality scale (1976) is nomothetic as it uses dimensions such as extrovert/introvert to measure personality which have been derived from a standardised questionnaire and which can be replicated in high numbers
• Adriaanse et al. (2011) found that restraint eating  was a predictor for the consumption of unhealthy snacks which is nomothetic as the research used a group of 469 participants rather than one individual

The individual reasons behind something like snack choice are lost in nomothetic research

Arguments for a nomothetic approach

• Being able to generalise laws of behaviour and compare groups of people is useful in predicting behaviour e.g. a questionnaire on post-natal depression can help to identify women who may be in need of medication and/or counselling
• Nomothetic research which applies statistical methods to test findings have enabled psychologists to identify what the norm for specific behaviours are e.g. IQ, which in turn strengthens psychology’s claim to be considered a science

Arguments against a nomothetic approach

• The nomothetic approach can highlight the what of behaviour but not the why; a large data set cannot explain the subjective experience of the individual which may actually be more important and useful than a statistically significant result
• Samples in psychological research are not always large enough from which to generate laws of behaviour e.g. Milgram’s (1963) obedience study used only 40 (male) participants so it would be unwise to state that this sample and their behaviour in the study is at all generalisable

The idiographic approach

• The aim of idiographic  research is to investigate the unique and subjective experiences of the individual
• Idiographic research tends to favour qualitative methods such as case studies which allow the researcher to use a range of methods to create a complete picture of the participant
• Idiographic research uses small samples -  often only a single participant - in order to generate data which is rich, thick and insightful
• Research such as Freud’s psychodynamic theory is idiographic as it seeks to understand the influence of the unconscious mind and childhood experience on an individual’s current behaviour
• The case of HM is an example of longitudinal research into the case of an individual with brain damage, using a range of measures (e.g. interviews, a star-tracing task, MRI scans) to better understand his anterograde amnesia

Idiographic research can reveal insight into more than just the individual studied as in the case of HM: his brain damage and amnesia led to key discoveries as to how the brain processes memory

Arguments for an idiographic approach

• The idiographic approach provides a comprehensive,  global understanding of the individual which in turn can lead to better insight into to inform therapies such as psychotherapy or Roger’s client-centred approach
• Nomothetic methods seek to ‘banish’ the individual from the process so the idiographic approach is one way to reinstate human beings as the focus of psychological research (which is, after all, the study of human behaviour)

Arguments against an idiographic approach

• It is not possible to generalise findings from idiographic research due to the restricted sample size which limits the overall usefulness of the research
• The methods used to study single individuals tend to be subjective which means that they may suffer from bias e.g. researcher bias, confirmation bias