The nomothetic approach studies a large number of people at once to collect quantitative research. They aim to generate explanations of behaviour that can be universal and generalised to entire populations, they argue that qualitative data doesn’t provide such generalisations.

For example, the biological approach seeks universal explanations for behaviour, and this can lead to drug therapies that can be used for all individuals. The research into fight or flight suggested that it was a universal response to stress. However, research by Taylor suggested otherwise (women have a ‘tend and befriend’ response). This shows how universal explanations ignore the differences that the idiographic approach focuses on.

In contrast, the idiographic approach focuses on individual insights and feelings, it collects qualitative data in order to gain in-depth and unique details on individuals rather than the numerical data.

For example, Freud’s (1909) analysis of Little Hans ( a boy whose fear of horses stemmed from his jealousy towards his father) consisted of 150 pages of notes. Freud spent a lot of time collecting detailed information about Little Hans in order to understand why he behaved the way he did.