Idiographic & Nomothetic Approaches (AQA A Level Psychology)

The idiographic-nomothetic debate

• The idiographic-nomothetic 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

  • People are studied in groups, with emphasis on large sample sizes

  • Methods which employ controlled conditions (e.g. lab experiments) err towards science are a feature of nomothetic research

• An idiographic approach seeks to understand the subjective experience of the individual

  • Individuals or small groups of people are studied, with emphasis on subjective experience

  • Methods such as case studies and interviews are a feature of idiographic research as they treat people as unique rather than as one element of a larger population

The idiographic approach to psychological investigation

• Idiographic research aims to investigate the unique, personal and subjective experience 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

  • This is known as method triangulation

• Idiographic research uses small samples -  often only a single participant

  • This is done to generate data which is rich, thick and insightful

  • The 'why' of behaviour is of more interest to idiographic researchers than the 'what' of behaviour e.g.

    • 'why did you feel that way?' rather than 'what did you feel?'

• Research within the humanistic approach is idiographic as it seeks to understand the 'journey' taken by an individual e.g.

  • the use of Maslow's hierarchy to chart individual progress

  • Rogers' client-centred therapy

• The case of HM is an example of longitudinal research into the case of an individual with brain damage and resulting anterograde amnesia, using a range of measures e.g.

  • interviews with HM, his family, the medical staff who attended him

  • a star-tracing task to investigate procedural memory

  • general observations of his behaviour

  • MRI scans to determine the nature of the brain damage

Evaluation of the idiographic approach to psychological investigation

Strengths

• The idiographic approach provides a comprehensive,  global understanding of the individual

  • This level of detail can lead to better insight into the complex and multi-layered nature of individual experience

  • Such insight can subsequently inform therapies designed to suit individual needs e.g. psychotherapy or Roger’s client-centred approach

• The idiographic approach is a way to reinstate the human as the focus of psychological research (whereas nomothetic methods tend to ‘banish’ the individual from the process of science)

  • This gives the idiographic approach high ecological validity

Limitations

• It is not possible to generalise the findings from idiographic research to general populations due to the restricted sample size and unique and subjective nature of idiographic studies

  • This limits the overall usefulness of the research

• The methods used to study single individuals tend to be subjective which means that they may be prone to various forms of bias e.g.

  • researcher bias - the researcher becomes overly involved in the research and loses their objectivity and impartiality

  • confirmation bias - the researcher looks for examples of behaviour/experience which align with their pre-existing ideas

  • Bias means that the research may lack credibility

The nomothetic approach to psychological investigation

• Nomothetic research aims to investigate groups of people to be able to generalise the findings 

  • This, in turn, can lead to the establishment of general laws of behaviour

  • Nomothetic research seeks to find similarities between people, what is commonly experienced by the majority

• 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 to generate robust quantitative data which can withstand statistical analysis e.g.

  • Bouchard's (1990) study on genetic inheritance and IQ used 1,500 pairs of twins and over 350 adopted and biological siblings

  • Van IJzendoorn & Kroonenberg (1988) collected data on 1,990 participants in cross-cultural replications of the Strange Situation

• Larger samples are used in nomothetic research as they provide a close approximation of the population

  • The primary goal of statistics is to generalise from a sample to a population,

  • This is more easily achieved if the sample size is large as anomalies tend to be 'smoothed out' by general trends/patterns of behaviour

• Research such as Eysenck’s personality scale (1976) is nomothetic as it uses dimensions such as extrovert/introvert to measure personality

  • These dimensions were initially derived from a standardised questionnaire

  • This means that they can be replicated in high numbers

• Adriaanse et al. (2011) found that restraint eating  was a predictor of the consumption of unhealthy snacks

  • This is nomothetic as the research used a group of 469 participants rather than one individual or a small group as would be used for a case study

Evaluation of the nomothetic approach to psychological investigation

Strengths

• Being able to establish general laws of behaviour and compare groups of people is useful in terms of predicting behaviour e.g.

  • a questionnaire on post-natal depression can help to identify women who may need medication and/or counselling

    • As symptoms of depression tend to be similar per person (e.g. low mood, lack of motivation), this enables practitioners to recognise the signs early and take remedial action

• Nomothetic research uses the features of science in its methodology

  • This means that studies are controlled, objective, standardised

  • Therefore nomothetic research has good reliability

Limitations

• 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 be more important and useful than a statistically significant result, particularly when it comes to the understanding of mental illness

  • This means that nomothetic research lacks external validity

• 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 the study findings are at widely generalisable