Why do some electricity bills compare your energy use with similar households? Why do hotels display signs saying, “Most guests reuse their towels”? Why do supermarkets place compostable produce bags right beside the fruit and vegetables?

These are all examples of nudges – small changes to the way choices are presented that encourage a particular behaviour without removing our freedom to choose.

What is Nudge Theory?

The foundations of Nudge Theory emerged from behavioural economics and cognitive psychology research during the 1970s. The term was later popularised by Richard Thaler and Cass Sunstein in their 2008 book, Nudge: Improving Decisions About Health, Wealth, and Happiness.

At its core, Nudge Theory recognises that most people want to make good decisions but can be held back by common human tendencies. We rarely make perfectly rational choices, habits often dominate behaviour, and context and defaults can significantly influence what we do. Nudge Theory therefore focuses on subtle changes to the environment that help guide people towards better outcomes.

“A nudge is an intervention that maintains freedom of choice but steers people in a particular direction.” – Cass Sunstein

Why nudges work

Nudges work because we often rely on mental shortcuts to navigate busy lives. This helps us make decisions quickly, but it also means seemingly small details – such as which option is presented first, what is selected by default or how much effort a task requires – can have a significant impact on what we do.

Several behavioural tendencies help explain why nudges can be effective.

Status quo bias means we are often inclined to stick with the existing or default option. This is why people are more likely to remain on paperless billing when it is selected as the default, even though they remain free to choose paper bills. The default reduces the need to make an active decision.

Loss aversion reflects our tendency to feel losses more strongly than equivalent gains. A message that highlights what someone may lose by not acting can therefore be more motivating than one focused only on the potential benefit. For example, reminding households how much money inefficient energy use could be costing them may attract more attention than simply promoting the benefits of saving electricity.

Social norms influence behaviour by showing us what other people are doing. When an energy bill compares a household’s electricity use with similar homes, it creates a reference point. People may adjust their behaviour because they do not want to be seen (even privately) as using considerably more than others.

Choice overload occurs when too many options make decisions harder rather than easier. Faced with lengthy forms, complex service choices or dozens of product options, people may delay the decision or avoid it altogether. Nudges can reduce this burden by simplifying information, highlighting a recommended option or breaking a task into manageable steps.

Present bias describes our tendency to prioritise immediate convenience over future benefits. We may know that saving money, exercising or reducing household waste will benefit us over time, but those outcomes can feel distant. Timely prompts, immediate feedback and small rewards help make the benefit feel more relevant in the moment.

Friction costs show how even minor obstacles can discourage action. A confusing form, an unnecessary extra step or an inconvenient collection point may be enough to stop someone following through. Removing friction can encourage a desired behaviour, while deliberately adding friction can discourage an unwanted one.

This is the central insight behind Nudge Theory: behaviour does not depend only on what people know or intend to do. It is also shaped by the environment in which the decision occurs. By making a preferred behaviour easier, clearer or timelier, nudges help close the gap between good intentions and action.

A common misconception is that a nudge is simply persuasion. It isn’t. Persuasion seeks to change what people think through information or argument. A nudge changes the environment in which a choice is made, making a particular behaviour easier, more noticeable or more attractive.

If you’re interested, here are 100 real-world examples of nudges in practice.

Nudges are not magic

Despite their potential, nudges are not a solution to every behaviour-change challenge. Organisations often jump straight to creating a nudge before first understanding behaviour correctly. Research can help identify the behaviour being targeted, why it currently occurs, the barriers and motivations involved, the key decision moments and the types of intervention most likely to resonate. Without this understanding, a poorly designed nudge may simply add more noise, complexity or friction.

It’s also important to note that nudges are most effective when people are already open to a behaviour and only need a small prompt or less friction to act. They are less likely to work when deeper barriers are involved, such as cost, limited capability, low trust or strongly held beliefs. In these situations, a nudge may help at the margins, but it cannot replace broader changes to services, systems or incentives.

The ethics of nudging

Nudge Theory also raises important ethical questions. Like any behavioural tool, nudges should be used responsibly. Their purpose is to help people make better decisions – not to manipulate or deceive them. Organisations must also consider who decides what constitutes a “better” outcome and whose interests the nudge ultimately serves. Effective nudges are transparent, preserve freedom of choice, act in people’s best interests and are continually tested to ensure they deliver genuine benefits rather than unintended consequences.

Before designing a nudge

Before designing a nudge, ask yourself:

• What behaviour are we trying to encourage?
• What is preventing it today?
• Where and when is the decision actually made?
• What small change could make the desired behaviour easier or more obvious?
• How will we know if it worked?

The most effective nudges don’t force people to change; they make the better choice the easier choice. Understanding how people think, what they value and where they encounter friction is what turns behavioural science into meaningful change.

Square Holes is a cultural insight studio.

We design mixed method explorations of people and culture beyond the category,  uncovering the patterns, tensions and shifts shaping behaviour to inform strategy, inspire innovation and enable confident decisions. Our studio model brings together the right mix of thinkers, researchers and specialists for each exploration. If you’re navigating change, entering a new market, or seeking deeper understanding of people and culture, let’s start a conversation >