Episode three: Diagnosis


Once the behavioural objective has been clearly defined, the next step is to diagnose the causes of current behaviour.

Why is this important?

A common mistake is focusing attention on solutions that treat symptoms as opposed to the root causes of existing behaviour.  Here the field of medicine can be used as a reference point to demonstrate the significance of such a mistake. A broken arm, for example, is really painful. This pain can be treated with painkillers. However, this treatment will only relieve one of the symptoms. The root cause of the pain is a broken bone which requires a very different treatment to be effectively solved. It is useful to think about behavioural challenges in this way too.


This phase can be divided in three steps:


The first step of the diagnosis phase is to draw on relevant behavioural science literature and the knowledge of experts within the team in order to generate hypotheses for why people are taking (or failing to take) certain actions. Exploratory field research approaches such as ethnography or journey analysis can also be used here to further stimulate the generation of hypotheses.

Some frameworks and tools to assist in generating hypotheses include:

  • The Decision-Action Model (Ideas42)

  • Journey mapping

  • Competing Pressures Model

  • The Three Worlds Model (Gravity Ideas)

  • Appreciation

  • Five Whys


Once a set of initial hypotheses has been generated, the next step is to conduct qualitative research and analyse existing data in order to better understand the hypothesised root causes. This will create a clearer picture of the drivers, bottlenecks, and contextual factors that have the most influence on behaviour.   



Role Play.png

User role playing


Ethnographic Research


Administratve Data Analysis


Usability Testing


Living Lab Analysis


The field research findings and data analysis should then be used to validate or exclude any of the initial hypothesised root causes as well as include any missing root cause explanations. These must then be prioritised based on their influence either in driving the existing behaviour or preventing the desired behaviour. In doing this, practitioners are able to enter the design phase with a good understanding of where best to focus when crafting interventions.

It is important to check intuitive decisions around prioritisation as it might be assumed that small subtle influences do not have much influence. As all behavioural scientists and nudge enthusiasts will tell you, often the smallest contextual factors can have a disproportionate level of influence on the behavioural outcome. In other words, do not underestimate the small things, but rather seek to understand how they might influence human psychology.

An example of intuition gone wrong

Often when companies advertise their product in order to increase adoption, or social organisations encourage people to donate to public awareness campaigns, they inadvertently expose themselves to negative social proof. A behavioural insight suggests that campaigns that aim to persuade their audience by showing how many people are not acting correctly actually works to signal that this ‘incorrect’ behaviour is the social norm. According to social proof theory, people rely on the behaviour of others to signal the correct behaviour so these kinds of strategies only work to further channel behaviour in that undesired direction.


Get in touch to solve your behavioural challenge here.