Behavioural Design

By Rivka Valkenberg

What Behavioural Design means

Behavioural Design applies insights from psychology and behavioral economics to one practical question: what would make this behavior easier to do? It is closely related to the field of behavior change and to choice architecture, a term popularized by Richard Thaler and Cass Sunstein for the way choices are presented (Thaler & Sunstein, 2008). Every situation has a choice architecture, whether anyone designed it or not.

Instead of focusing on what is inside people’s heads (beliefs, willpower, knowledge), a Behavioural Designer looks at what surrounds them: the default option, the number of steps, the timing of a reminder, what other people appear to do.

A widely cited example concerns organ donation. Countries where people are donors by default, with the option to opt out, show much higher consent rates than countries where people must actively opt in (Johnson & Goldstein, 2003). Similarly, when employers switched retirement plans from opt-in to automatic enrollment, participation rose sharply (Madrian & Shea, 2001). In neither case were people persuaded of anything new. The easiest path changed.

The intention-action gap

People often intend to act and then don’t. Research shows that intentions predict only part of what people actually do (Sheeran, 2002). This gap between knowing and doing is where Behavioural Design works. Information, incentives and instructions can help, but on their own they assume that people decide mainly through deliberate reasoning.

Two systems

A common way to describe this is the distinction between two modes of thinking, popularized by Daniel Kahneman (2011). System 1 is fast, automatic and intuitive. It responds to what feels familiar, safe and easy. System 2 is slow, deliberate and analytical. It weighs arguments.

Much everyday behavior runs on System 1, while System 2 often explains choices after they have been made. This helps explain why a well-reasoned argument can win agreement and still not change behavior. The two systems are a helpful model, not a description of two separate parts of the brain.

Engines and brakes

Many practitioners describe behavior as the result of opposing forces. This idea draws on the “forces of progress” in Jobs-to-be-Done research (Moesta, 2020) and is used in practical models such as the Influence Framework of SUE Behavioural Design (n.d.). Two forces drive change. Two hold it back.

• Engine · Pains: “The way we work now is frustrating.”
• Engine · Gains: “The new way sounds better.”
• Brake · Anxieties: “What if I can’t do it? What if it goes wrong?”
• Brake · Comforts: “What I do now is familiar, and it works well enough.”

Change efforts usually concentrate on the engine: more benefits, more urgency, more enthusiasm. Behavioural Design pays at least as much attention to the brakes. When anxieties or comforts are strong, adding pressure can increase resistance. Reducing a brake often has more effect.

Motivation, ability and prompts

BJ Fogg’s behavior model states that a behavior happens when motivation, ability and a prompt come together at the same moment: B = MAP (Fogg, 2009, 2019). If a behavior is not happening, one of the three is missing. Making a behavior easier is often more reliable than trying to increase motivation.

The UK’s Behavioural Insights Team (2014) summarized practical guidance in the EAST framework: make it Easy, Attractive, Social and Timely.

• Easy: Remove steps, reduce effort, set helpful defaults. For example: A pre-filled form. A default option.
• Attractive: Make it noticeable and personally relevant. For example: A personal message, visible progress.
• Social: Show what others do; make commitments visible. For example: Tax letters stating that most people pay on time (Hallsworth et al., 2017).
• Timely: Prompt people when they are most open to change. For example: A new job, a new year, the moment before a decision.

A design process

Behavioural Design is usually iterative: define, diagnose, design, test and refine. Practitioners describe the target behavior concretely, investigate the forces around it together with the people involved, design small interventions and test their effect in the real context. Because brakes differ between groups and situations, an intervention that works in one setting may not work in another.

Evidence and practical limits

Behavioural Design is grounded in well-researched principles from behavioral science. Several are supported by strong evidence, including from field experiments outside the lab. Defaults consistently influence choices (Jachimowicz et al., 2019). If-then plans meaningfully improve follow-through (Gollwitzer & Sheeran, 2006). And social-norm messages have increased tax compliance at national scale (Hallsworth et al., 2017).

How large an effect is depends on the context. Reviews of nudges as a broad category show that results differ widely between interventions and settings (Mertens et al., 2022; Maier et al., 2022). Interventions run at scale by government nudge units produce effects that are real and cost-effective, but smaller than those reported in academic journals (DellaVigna & Linos, 2022).

This is why Behavioural Design works as a process rather than a toolkit. A principle that is proven in general still has to fit the specific situation, so practitioners diagnose the barriers first and test what works. Behavioural Design also cannot replace adequate resources, fair policies or structural change. A well-designed form does not fix an unworkable process.

Ethics

Because Behavioural Design influences behavior, it raises ethical questions. Thaler (2015) proposed that nudges should be transparent and never misleading, easy to opt out of, and likely to improve the welfare of the people being nudged. Designs that deliberately make things harder against people’s own interest, such as a subscription that is difficult to cancel, are called sludge (Thaler, 2018). A simple test: could the intervention be explained openly to the people it is aimed at?