Specification: Idiographic and nomothetic approaches to psychological investigation.

What is the aim of psychological research: Is it to discover universal laws of human behaviour, or to develop an in-depth understanding of unique cases? This is the central argument in the debate between the idiographic and nomothetic approaches.

The idiographic approach

The term ‘idiographic’ comes from the Greek word ‘idios’, which means ‘own’ or ‘private’. Psychologists who take an idiographic approach focus on the individual and emphasise the unique personal experience of human nature. This means they favour qualitative research methods, such as the case study, unstructured interviews and thematic analysis, which allow an in-depth insight into individual behaviour. The idiographic approach does not seek to formulate laws or generalise results to others.

Case studies provide an interesting example of an idiographic approach, as they provide an in-depth insight into an individual or small group which can be used to evaluate a theory. For instance, Shallice and Warrington (1970) examined the case of Patient KF, who experienced a motorbike accident. KF’s short-term forgetting of auditory information was greater than his forgetting of visual information, suggesting that short-term memory (STM) consists of multiple components. Consequently, Patient KF undermines the Multi-Store Model of Memory, suggesting that STM is not one unitary component. Therefore, an individual case study can highlight flaws within a theory and significantly undermine other research.

Another example of an idiographic approach comes from Freud’s use of case studies. Freud conducted very detailed investigations into the lives of his patients to understand and help them overcome their psychological disorders. His most famous case studies include Little Hans and The Rat Man. While Freud did try to produce generalisations from his case studies, they are still viewed as an idiographic approach because each person’s psychological disorder derived from their unique childhood experiences.

Evaluation

The idiographic approach is unable to produce general laws or predictions about human behaviour, and that severely limits its usefulness as a source of practical knowledge about the diagnosis and treatment of psychological disorders. For a discipline so dedicated to the application of its scientific understanding, this is a devastating limitation. Furthermore, many psychologists criticise the idiographic approach for its fundamentally unscientific nature. The emphasis on in-depth data collection and the difficulties in arriving at justifiable generalisations contradicts the central purpose of any mature science: to explain the most variation in the fewest possible terms so that phenomena can be predicted and ultimately controlled. Research practices that do not address these goals can seem scientifically pointless.

• However, idiographic researchers respond to these criticisms by emphasising the evidence-based nature of their descriptions and conclusions, and the critical awareness embedded in research techniques like reflexivity, and often claim that the validity of their findings is more secure than that which rests entirely on statistical analysis. As Allport noted, when introducing the terms into American psychology in 1937, it is only through the understanding of single individuals that psychologists can hope to predict how such individuals will behave in each situation.

However, there are numerous strengths of taking an idiographic approach, and a case study method is a powerful tool for evaluating psychological theories. The case of Patient KF (Shallice and Warrington, 1970) exposed a limitation of the Multi-Store Model of Memory, by providing evidence that our STM comprises of at least two components (auditory and visual memory) and not one, as stipulated by Atkinson and Shiffrin. Consequently, a single case study can generate further research into a particular phenomenon (e.g. memory), which contributes to the development of new theories that further our understanding of human behaviour.

• While case studies can highlight a flaw in psychological theories and prompt further research, the case study method and other qualitative methods are incredibly time-consuming. Freud’s case study of Little Hans consists of almost 150 pages of verbatim quotes from Little Hans’ father, as well as detailed descriptions of the events in Little Hans’ life. Freud did go on to create universal theories of personality development during childhood; however, these were based on limited and unrepresentative case studies that many psychologists would discredit

The nomothetic approach

The term ‘nomothetic’ comes from the Greek word ‘nomos’ which means ‘law’. Psychologists who take a nomothetic approach are concerned with establishing general laws, based on the study of large groups of people, and the use of statistical (quantitative) techniques to analyse data. This means that experiments, correlations, psychometric testing and other quantitative methods are favoured among nomothetic researchers.

The nomothetic approach is the main approach within scientifically oriented psychology. For example:

• Biological Psychologists take a nomothetic approach when explaining psychological disorders, such as OCD and depression. They typically pinpoint biological factors, such as neurotransmitters, that are responsible for such disorders and use biological therapies (e.g. drugs) to treat all patients.

• Behaviourists, such as Pavlov and Skinner, conducted experiments with animals to establish laws of learning (classical and operant conditioning) that could be generalised to humans and non-human animals.

• Cognitive psychologists, such as Atkinson and Shiffrin, developed general laws, such as the Multi-Store Model of Memory, which they believed could be generalised to everyone.

• Social psychologists, such as Milgram and Asch, used a nomothetic approach to create general conclusions about human behaviour: that situational factors are responsible for both obedience and conformity.

• Furthermore, in the area of psychopathology, classification manuals such as DSM-V and ICD-10 take a nomothetic approach, as they classify people with psychological disorders based on specific symptoms.

Evaluation

Unlike the idiographic approach, the nomothetic approach is considered as generally scientific. The use of experimental (quantitative) methods, controlled measurement and the ability to predict behaviour, are all seen as strengths of the nomothetic approach. Furthermore, controlled methods allow for replication to examine the reliability of findings which has helped psychology establish itself as a scientific discipline. The development of theories and empirical testing are just one of the key features of science that are employed by the nomothetic approach.

Furthermore, because the nomothetic approach is viewed as scientific, it is useful for predicting and controlling behaviour. For example, biological psychologists take a nomothetic approach when explaining obsessive-compulsive disorder (OCD) and claim that OCD is caused by higher levels of dopamine and lower levels of serotonin. Drug therapies are developed based on nomothetic research and work by redressing a biological imbalance. SSRIs are used to treat OCD and increase the availability and uptake of serotonin, thus reducing the anxiety associated with OCD, which helps to improve the lives of people suffering from this condition.

• However, as drug treatments are not successful for all patients, some psychologists argue that alternate treatments (e.g. Cognitive Behavioural Therapy), which are based on an idiographic approach, are more suitable for treating individuals with such conditions, as they seek to understand and explain the disorder from a patient’s point of view.

Furthermore, some psychologists argue that the nomothetic approach loses sight of the ‘whole person’, due to its fixation on quantitative data and statistical analysis. Moreover, these psychologists also claim that the nomothetic approach only provides a superficial understanding of human behaviour. For example, Milgram’s research found that 65% of participants obeyed an authority figure and inflicted a 450-volt electric shock because they were ordered to do so. However, the results fail to explain why each person obeyed, and there may have been very different circumstances that led to the obedience found in each participant.

• Idiographic researchers would argue that Milgram’s research only allows us to make predictions on groups and not on individuals. While Milgram might predict that 65% of the population would obey an unjust order, he is unable to predict what an individual would do accurately. Allport (who first coined the term idiographic) argued that it is only by understanding an individual that we can make accurate predictions of individual behaviour.

Extension: A combined approach

Holt (1967) argues that the idiographic/nomothetic distinction is a false distinction. Many approaches in psychology take advantage of both approaches and therefore, the two approaches can be viewed as complementary rather than contradictory. For example, while cognitive psychologists typically take a nomothetic approach and create general laws of cognitive processes (e.g. the Working Memory Model), they also take advantage of the idiographic approach when using case studies to provide evidence for a particular theory (e.g. Patient KF, Shallice and Warrington, 1970). In reality, many research studies make use of both approaches, and it could be argued that the distinction between idiographic and nomothetic is meaningless and that psychologists should employ both methods depending on the nature of the research question.

Critical thinking

Consider the topic Psychopathology. Which psychological disorders are treated using a nomothetic approach and which are treated using an idiographic approach?

Are some disorders (e.g. OCD, Depression or Phobias) treated using both approaches? If so, which approach has produced better success rates?

Can you think of another example of where the idiographic and nomothetic approach have been combined?

Possible exam questions

1. Explain what is meant by the terms idiographic and nomothetic. (4 marks)

2. Two psychologists wanted to study delinquent behaviour in schools. One psychologist chose to conduct a case study on a pupil called Nathan, who has ADHD, whereas the other psychologist chose to examine an entire primary school population to come up with a theory about delinquent behaviour. Using your knowledge of the idiographic and nomothetic approaches, outline one strength of both approaches in relation to this scenario. (4 marks)

3. Discuss idiographic and nomothetic approaches to psychological investigation. (16 marks)