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Driving Behaviour Change: The Building Blocks of Programme Theory

Systemic change happens through changes in what actors do. But what actually drives behaviour change? This page introduces a simple framework: four building blocks for understanding and influencing how people and organisations change their behaviour.

Whether you're designing an intervention or evaluating one, you need to understand why actors change their behaviour. Not just that they changed, but why: what motivated it, what enabled it, what was stopping them before.

This matters for strategy because it helps you design interventions that address the real barriers to change. And it matters for evaluation because it helps you understand whether observed changes are likely to be sustained, and what role your programme played in producing them.

The Building Blocks framework strips the process of behaviour change down to its essential elements. It's designed to apply in any situation where you're trying to get someone, whether an individual, a firm, or an organisation, to do something differently.

Why behaviour change is central to systemic change

Systems are made up of actors taking actions. When we talk about systemic change, we're ultimately talking about changes in what actors do. Those changes aggregate into different patterns across the system.

This means behaviour change is the mechanism through which systemic change happens. If you want to understand how a system has changed, you need to identify whose behaviour has changed and how. If you want to design a strategy for changing a system, you need to think about whose behaviour you're trying to influence and what would cause them to change.

The Building Blocks framework provides a structured way to think about this, whether you're designing an intervention or analysing what happened after the fact.

How this fits together: In the Six Steps process for measuring systemic change, identifying behaviour changes is Step 4, and analysing what drove those changes is Step 5. The Building Blocks framework is the tool for Step 5. It helps you understand why the behaviour changes you've observed actually happened.

The four building blocks

The framework has four elements. Together, they describe the essential components of any behaviour change process:

1. Behaviour Change

The specific change in what an actor does. This is what you're trying to achieve (in strategy) or what you've observed (in evaluation). It needs to be concrete and specific: not "improved capacity" but "farmers started using certified seeds" or "retailers began offering credit to smallholders."

Example: Seed importers start importing higher-quality seeds.

2. Rationale

The reason why the actor might change their behaviour: the benefit they expect to receive. This is broader than just financial incentives. It might include learning opportunities, reduced risk, social recognition, political advantage, or alignment with values. The rationale is inherently uncertain: it's an estimate of future benefits that depend on others' actions.

Example: Importers expect that higher-quality seeds will command premium prices and increase customer loyalty.

3. Blockers

What's preventing the behaviour change from happening, even when there's a rationale for it. Blockers might include uncertainty about whether the benefits will materialise, lack of information about how to change, insufficient resources or capabilities, or risks that outweigh the expected benefits. Understanding blockers is often the key to designing effective interventions.

Example: Importers are uncertain about demand for higher-quality seeds and don't know which suppliers are reliable.

4. Change Resources

What gets introduced, deliberately or incidentally, to enable the behaviour change. Change resources address blockers and strengthen rationale. They come in three broad types: new input resources (like technical information or skills), new information about existing resources (like market data that reveals unmet demand), or removal of blockers (like regulatory changes that reduce risk).

Example: A programme provides market research showing demand for quality seeds, and connects importers with certified suppliers.

The logic

An actor will change their behaviour when the rationale is strong enough and the blockers are sufficiently reduced or removed. Change resources work by strengthening the rationale, reducing blockers, or both. The behaviour change itself is the outcome: what actually happens as a result.

Using the framework for strategy design

When designing an intervention, the Building Blocks help you think through what it will actually take to get actors to change their behaviour:

  1. Specify the behaviour change you're targeting. Be concrete. Who exactly needs to do what differently?
  2. Understand the rationale. Why would this actor want to change? What benefit would they get? Is the rationale strong enough?
  3. Identify the blockers. If there's a rationale for change but it's not happening, something is blocking it. What is it? Uncertainty? Lack of information? Missing capabilities? Risk?
  4. Design change resources that address the blockers. What would it take to remove or reduce those blockers? What resources could you introduce?

This is a more rigorous approach than simply assuming that providing information or training will lead to behaviour change. It forces you to think about why the change isn't already happening, and to design interventions that address the actual barriers.

Using the framework for evaluation

When evaluating whether and why behaviour change has occurred, the Building Blocks provide a structure for analysis:

  1. Document what behaviour changes have occurred. What are actors doing differently? (This is Step 4 in the Six Steps process.)
  2. Analyse the rationale. Why did actors change? What benefits did they expect or receive?
  3. Identify what blockers were removed. What was preventing change before? What changed to remove those barriers?
  4. Trace the change resources. What enabled the change? Where did those resources come from: your programme, other actors, or changes in the environment?

This analysis helps you understand not just that change happened, but why. This is essential for learning, for assessing sustainability, and for making credible claims about your programme's contribution.

Beyond financial incentives

A common mistake in behaviour change thinking is to focus only on financial incentives, assuming that if you can make something profitable, people will do it. The Building Blocks framework takes a broader view.

Rationale includes any benefit the actor might receive:

And blockers can be about more than just money:

Effective interventions often work on these non-financial dimensions, such as reducing uncertainty, providing information, building relationships, and changing norms, rather than simply subsidising behaviour.

How this connects to system mapping

The Building Blocks framework applies at the actor level. It's about understanding why a specific actor changes their behaviour. But actors exist within systems, and their behaviour changes aggregate into systemic change.

This is where system mapping comes in. A good system map identifies the actors involved and the actions they take. The Building Blocks framework then helps you analyse, for each actor whose behaviour you're trying to change or have observed changing, what drove that change.

The two frameworks work together:

Getting started

The full framework is set out in the paper The Building Blocks of Programme Theory: How to Get Better at Driving Behaviour Change (with Rachel Shah). It includes more detail on each building block, examples, and discussion of how the framework connects to broader theories of change.

Related papers:

Read the full paper

The Building Blocks of Programme Theory: How to Get Better at Driving Behaviour Change

Download on ResearchGate →