Using behavioural science to supercharge your fundraising

At its heart, fundraising is about people – understanding how they think, feel and make decisions. And that’s where behavioural science comes in. It helps us make sense of what really drives action, and how small changes in how we present choices can have a big impact on results.

If you’ve worked with a creative agency, especially on direct mail, chances are you’re already using behavioural science in your fundraising without even realising it. Things like suggested donation amounts or the odd deadline for response aren’t just creative flair – they’re rooted in proven behavioural principles.

But there’s still lots of untapped potential. Behavioural science principles aren’t just for mail packs. They can (and should) show up across the whole supporter journey – from donation forms and welcome emails to lead generation campaigns and thank-you pages. When used thoughtfully, they make giving feel easier, more rewarding and more natural, as well as increasing response and engagement.

In this blog, we’ll walk through six practical behavioural science principles that every fundraiser should know.

1. Anchoring

We tend to latch onto the first number or piece of information we see and it becomes our mental benchmark. In fundraising, this is often your suggested donation amounts. If £50 is the first option shown, £20 feels modest by comparison and £100 no longer seems unreasonable.

It’s no coincidence that charities often present supporters with a choice of three donation prompts – whether in a direct mail pack, an email or on a website. This structure gives just enough variety to feel like a choice, while subtly guiding the donor toward the middle or higher amount. The first figure acts as an anchor, shaping how the rest are perceived.

And where charities have the insight and capability to anchor based on a supporter’s past giving behaviour – for example, showing a slightly higher suggested donation amount than someone’s past gift – this becomes even more powerful. It allows for a tailored experience that can nudge supporters toward incrementally higher gifts over time.

2. The default effect

Have you ever noticed how some donation forms already have the monthly gift option selected for you? Or how certain checkboxes – like Gift Aid – are ticked by default? That’s not an accident. It’s a classic example of a behavioural principle in action: most of us stick with the option that’s already chosen.

Defaults work because they remove friction. And they’re particularly practical in online settings – like donation forms, lead generation campaigns or newsletter sign-ups – where you can guide supporters without them needing to make lots of extra decisions.

Setting regular giving as the default, for example, is a simple but effective way to nudge people towards a higher-value action. Just make sure it’s transparent and easy to change – supporters should always feel in control.

3. Social proof and the bandwagon effect

Have you ever looked at someone’s JustGiving page to see how much others have donated before deciding what to give yourself? You’re not alone – and that’s social proof in action. When we’re unsure how to act, we take cues from those around us. Seeing what other people do helps us decide what’s normal, expected or generous.

That’s why things like supporter testimonials, donor counters or ‘Join others’ messaging can be so effective. They show potential supporters that people like them are already getting behind the cause – and that they won’t be the first or only one to step up.

It doesn’t have to be complicated. Even a simple line in an email – ‘More than 500 people have already donated this week’ – can create a sense of momentum and give people confidence to act.

4. Loss aversion and framing

We’re naturally more motivated to avoid a loss than to gain something of equal value. It’s just how our brains are wired – losing £10 feels worse than finding £10 feels good. And that same principle applies to fundraising messages.

So instead of saying ‘Help provide clean water’, you might get a stronger response with ‘Stop a child from going without clean water’. The impact is the same but the framing is different – and the second taps into a stronger emotional trigger.

This doesn’t mean every message needs to sound dramatic or negative. It’s about testing how you present the need – and understanding that subtle shifts in language can lead to noticeable shifts in behaviour.

5. The principle of reciprocity

You know that feeling when someone does something kind for you and you want to return the favour? That’s reciprocity, and it’s a powerful part of how we build relationships. In fundraising, the same thing applies.

Ever wondered why some cold acquisition packs include pens, stickers or Christmas cards? Or why value exchange campaigns – like offering a free guide or downloadable checklist – are so popular right now? It’s because when supporters feel they’ve been given something, they’re more likely to give back.

It doesn’t have to be fancy or expensive. What matters is that it feels thoughtful. A useful resource, a warm thank you or an exclusive piece of content can all help build a sense of connection and goodwill , which then makes a donation feel like a natural next step.

6. Urgency and scarcity

Ever rushed to donate because a match fund was ending at midnight or because there were “just a few hours left” to hit a campaign target? That sense of time running out is no accident; it’s tapping into our natural fear of missing out. When something feels limited – whether it’s time, money or opportunity – we’re more likely to act quickly. That’s why deadlines, countdowns and urgency messages can have a big impact. They create momentum, help overcome procrastination and make the decision feel more immediate.

Of course, this only works if it feels genuine. Supporters can spot a fake deadline a mile off, so the trick is to use urgency sparingly – and only when there’s a real reason to act now.

How to get started

If this is all new to you, don’t worry; you don’t need to overhaul everything at once. Start by looking at one area of your fundraising where small changes could make a difference. Your donation form, for example, is a great place to begin.

Ask yourself:

• Are we guiding donors with clear, simple choices?
• Are our suggested donation amounts working for us, or could we be anchoring more effectively?
• Are we using social proof or urgency in a thoughtful, honest way?
• Is there a moment in our supporter journey where we could give something meaningful before we ask?

Pick one principle to focus on, make a small change, and track the results. The beauty of behavioural science is that it’s designed to work in the real world – so you can test, learn and adapt as you go.

Final takeaways

• Behavioural science isn’t about manipulating donors – it’s about making giving easier, more intuitive and more rewarding.
• You don’t need a big budget to get started – many of the most effective changes are simple, low-cost tweaks to messaging, design or structure.
• It’s not just about the appeal mailing – think about where else in the supporter journey you can apply these principles, from donation pages to welcome emails to lead generation campaigns.
• Start small, test often – one clear change is better than five all at once. Learn what works for your audience and build from there.

And finally: stay transparent, ethical and supporter-first. Behavioural science is most effective when it builds trust and strengthens long-term relationships.

Emma O’Reilly, Senior Consultant
May 2025

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