You know the scenario. There is a problem - people eat unhealthily, employees do not use a new system, citizens sort their waste incorrectly - and the reflex is always the same: we need to inform people better. More leaflets, more campaigns, more explanation. It sounds logical. If people only knew how things work, they would surely adjust their behaviour?

But they do not. And that is not a matter of poor communication. It is a fundamental misunderstanding of how human behaviour works.

The gap between knowledge and behaviour

The idea that information leads to different behaviour is so deeply rooted that it has a name in behavioural science: the information deficit model. The model assumes that undesired behaviour stems from a lack of knowledge. Fill that gap, and the behaviour changes by itself.[1]

The problem? This model is wrong. And the evidence is overwhelming.

Take smoking. In the Netherlands, 97% of smokers know that smoking is harmful to their health. Yet a significant proportion continue to smoke. Or take energy saving: research shows that the vast majority of households know they can save energy by showering for shorter periods or turning down the heating. But the thermostat is still set to 21 degrees.[2]

The pattern is universal: knowing is not doing. And yet communication professionals, policymakers and managers keep clinging to the belief that more information is the answer.

97% of smokers know that smoking is harmful. Yet a large proportion continue to smoke. Knowledge is not the problem. Behaviour is the problem.

Why informing fails: three explanations

From a behavioural science perspective, there are three fundamental reasons why information alone does not change behaviour.

1. The brain runs on autopilot

Most behaviour is driven by what psychologist Daniel Kahneman calls ‘System 1’: the fast, automatic and unconscious thinking system. Information appeals to ‘System 2’ - the slow, conscious and analytical system. But System 2 is lazy. It is only activated when truly necessary, and switches off again as quickly as possible.

If you give someone a leaflet about healthy eating, you are appealing to System 2. But when that same person comes home tired in the evening and walks past the chip shop, System 1 takes over. And System 1 chooses convenience, not information.

2. The intention-action gap

Even if information does lead to an intention to act differently, there is still an enormous gap between intention and action. Researchers call this the intention-action gap. Meta-analyses show that only 47% of intentions are actually translated into behaviour.[3]

In other words: even in the best-case scenario - where your information convinces someone of a new intention - the chance that it actually leads to different behaviour is less than a coin toss.

3. Context beats intention

Behaviour is determined far more by the environment than by individual knowledge or beliefs. The default option on a form, the layout of a canteen, the social norm within a team - these contextual factors often determine behaviour more than all information combined.

A famous example: when organ donation in some countries was changed from opt-in to opt-out (the default), the percentage of donors rose from approximately 15% to over 90%. Nobody received more information. The context changed.

What does work: four principles

If information is not the answer, then what is? Behavioural science offers four principles that are demonstrably more effective than informing.

1. Change the default, not the opinion

The most powerful behavioural intervention is often the simplest: change the default option. People predominantly choose the default, regardless of their knowledge or convictions. Want more employees to participate in a pension scheme? Make participation the default. Want more people to use green energy? Make green the default.

This works because leveraging the status quo bias - our tendency to maintain the existing situation - is far more powerful than trying to convince someone rationally.

2. Remove friction

Every obstacle between intention and action - an extra click, a complicated form, an unclear next step - dramatically reduces the chance of the desired behaviour. Instead of convincing people that they should do something, make it easier to do it.

Amazon understood this like no other with their 1-click ordering. No extra information, no persuasion - just less friction.

3. Show what others do

People are social creatures. We look at what others do, especially when we are uncertain about the right behaviour. Social proof is one of the strongest behavioural mechanisms we know.

Instead of communicating why something is important, communicate how many people are already doing it. “80% of your colleagues submit the form within a week” is more effective than an explanation of why the form matters.

4. Choose the right moment

Behaviour is most influenceable at moments of transition - a new job, a move, the start of a new year. At these fresh start moments, System 2 switches on briefly and people are more receptive to change.

Communication professionals who align their message with these transition moments achieve more than those who continually repeat the same message.

What does this mean for communication professionals?

This does not mean that communication is pointless. It means that the role of communication shifts. From informing to facilitating. From broadcasting to designing.

The communication professional who understands behavioural science asks different questions:

This is the core of Behavioural Design for communication professionals: shift your focus from the message to the choice environment. It is not what you say that determines behaviour, but how you design the context in which people make decisions.

And that is precisely what informing can never achieve. Information changes knowledge. Context changes behaviour.