Every day you are nudged. When the supermarket places vegetables at the entrance and crisps at the back. When your employer automatically enrols you in the pension scheme. When the staircase in the station has been painted so invitingly that you ignore the escalator entirely. Nudging is everywhere, but most people don’t understand how it works. And that is precisely why it is so powerful.

This guide explains everything you need to know about nudging: the definition, the psychology behind it, proven examples, the ethics, and how you can apply it yourself.

What is nudging?

The term nudge, a gentle push, was introduced by behavioural economist Richard Thaler and legal scholar Cass Sunstein in their landmark book Nudge (2008, Yale University Press). Their definition:

A nudge is any aspect of the choice architecture that alters people’s behaviour in a predictable way without forbidding any options or significantly changing their economic incentives.

Simply put: nudging is steering behaviour without mandates or bans. You change the choice architecture, the environment, the order, the presentation, so that people automatically make better choices, without restricting their freedom.

Thaler and Sunstein call this libertarian paternalism: you help people make better decisions (paternalistic), but always leave them free to choose otherwise (libertarian). For a detailed explanation of this concept, see our article on libertarian paternalism.

Nudge vs. coercion vs. manipulation

The critical distinction: a nudge is always opt-out. You can go around it. A ban is not. And manipulation? That is when you influence someone outside their awareness, in your interest rather than theirs. More on that boundary in the ethics section below.

Why does nudging work?

To understand why nudging is so effective, you first need to accept what science has known for decades but what we still apply too rarely in practice: people are not rational decision-makers.

Nobel Prize winner Daniel Kahneman described in Thinking, Fast and Slow (2011) two systems in our brain:

This means the vast majority of decisions people make, what to eat, how to save, whether to register as an organ donor, are not the result of rational deliberation, but of automatic, contextual processes. Nudges align with System 1. They make the desired behaviour the path of least resistance.

Make it as easy as possible for someone to perform behaviour without having to think. That’s the secret to success.

We consistently choose comfort over effort. We follow the default option. We do what the people around us do. We react to what is immediately visible. Nudges harness these stubborn patterns, rather than fighting them.

Nudging examples that have been proven to work

Theory is fine, but nudging truly shines in practice. Here are the most compelling examples, all backed by measurable results.

The fly in the urinal (Schiphol Airport)

The most famous nudge experiment in the world took place at Amsterdam Airport Schiphol. A small image of a fly was etched into the urinals in the men’s toilets. The result: spillage dropped by approximately 80%. Men automatically aimed at the fly, without consciously thinking about it. No sign. No fine. Just a smart adjustment to the context.

Organ donation and the power of defaults

In countries with an opt-out system for organ donation, where you are registered unless you actively opt out, participation is close to 100%. In countries with an opt-in system, where you must actively sign up, participation is only 20 to 27%.[4] Same people, same values, a different default. This is the most powerful evidence for the influence of choice architecture on behaviour at scale.

Cafeteria: healthy food at the front

When schools and corporate canteens placed healthy food prominently, at eye level, as the first option, in attractive packaging, sales of vegetables and fruit rose by an average of 25%. Nothing was banned. The unhealthy food remained available. Only the order and presentation changed.

The staircase as an instrument

A classic experiment across multiple offices and stations: by decorating staircases with artwork, music and cheerful markings, staircase use rose by approximately 25% while lift and escalator use declined. The choice remained free, but the staircase was made more attractive.

Amazon and removing friction

The introduction of Amazon’s ‘one-click buying’ was a textbook nudge: by removing all friction from the purchase process, conversion increased enormously. Not through better arguments or higher discounts, but through fewer steps. Simplicity eats willpower for breakfast.

The ethics of nudging

Nudging raises a legitimate question: when does a clever adjustment to context become manipulation? The answer lies not in the technique itself, but in the intent.

At SUE, we apply a clear ethical test:

If your intent is to help people make better decisions that are in their interest, it is nudging. If your intent is to influence people in your interest, at their expense, it is manipulation.

Two additional criteria make the distinction concrete:

  1. Transparency: an ethical nudge can withstand scrutiny. You can explain what you are doing and why. Manipulation collapses the moment it is exposed.
  2. Opt-out: a nudge always leaves an exit open. Dark patterns, such as hidden unsubscribe buttons, misleading defaults or fake urgency, are the opposite of nudging. They remove freedom of choice rather than respecting it.

The good news: nudging works best when it is in the user’s interest. When people later discover they were nudged towards something that did not serve them, it generates distrust, the opposite of what you want to achieve.

Nudging in organisations

Nudging is not just for governments and behavioural economists. It is a powerful instrument for anyone who wants to influence the behaviour of others, ethically and effectively.

HR and employee wellbeing

Automatic enrolment in company pension schemes, making healthy meals the default in the canteen, placing fruit bowls by the coffee station: HR professionals can use nudging to help employees make healthier and financially wiser choices without paternalistic coercion.

Government and public policy

That nudging works in public policy is perhaps best documented. From the British Behavioural Insights Team (also known as the ‘Nudge Unit’) to the American SBST: governments worldwide use nudging to influence tax payment behaviour, health behaviour and energy consumption. For professionals in the public sector, nudging is one of the most cost-effective policy instruments available.

UX and digital design

Every UX decision is a nudge. Which option is ticked by default? Which button is largest? What do you see first? UX designers who consciously apply nudging, in the interest of the user, build better products. See also our article on sludge: the dark counterpart of nudging that deliberately adds friction to block behaviour.

Communication and marketing

Framing, defaults, social norms, anchoring: communications professionals and marketers work daily with the building blocks of nudging. The difference between good and great lies in applying what behavioural science teaches us consciously and systematically.

How to get started with nudging

Applying nudging ad hoc leads to nudges that work by chance. Systematic nudging starts with a good diagnosis. At SUE we use the SUE Influence Framework for this: a model that makes the unconscious forces behind behaviour visible.

Step 1: Diagnose with the SUE Influence Framework

Before you design a nudge, you need to understand what is holding people back or propelling them forward. The Influence Framework distinguishes four forces:

You do not change behaviour by working on the behaviour itself. You change behaviour by influencing the forces that drive it. Influence is far more judo than karate: you work with the forces that are already there, not against them.

Step 2: Choose the right nudge technique

Based on the diagnosis, you choose the most effective intervention. Is there a Comfort you need to break through? Then a commitment device works well. Is there an Anxiety holding people back? Then removing uncertainty works better than adding benefits. Is the desired behaviour simply too complicated? Then the solution is almost always: reduce the friction.

Simplicity eats willpower for breakfast.

The most effective nudges simultaneously remove friction from the desired behaviour and add friction to the undesired behaviour. That is what makes defaults so powerful: they make the desired behaviour automatic and the alternative something extra.

Step 3: Test and measure

A nudge is a hypothesis. You think it will work, but only an A/B test or a pilot tells you whether it actually does. Behavioural science teaches us that our intuitions about what drives behaviour are regularly wrong. Always test. Always measure. Iterate on the basis of evidence.

Conclusion: nudging is strategy, not a trick

Nudging is not a gimmick. It is a fundamentally different way of thinking about behaviour change. Instead of persuading people with arguments, information or financial incentives, you change the environment so that the desired behaviour is the easiest option.

The science is clear: people are not rational decision-makers. They follow the default, choose comfort over effort, and are steered by the context around them. Nudging uses this insight to design positive change, without coercion, without manipulation.

Do you want to learn to apply nudging professionally? In the Behavioural Design Fundamentals you learn step by step how to use the SUE Influence Framework to analyse behaviour, spot opportunities for nudging and design effective interventions.