CRO is just psychology, measured
How behavioural science can supercharge your conversion rate optimisation in digital marketing.
The highlights
If you want the short version: people aren’t logical. They behave like Homer Simpson, not Spock. They rely on emotion, instinct and mental shortcuts to make thousands of small decisions every day.
That means the role of conversion rate optimisation (CRO) isn’t to perfect design – it’s to understand decision-making. Once you learn to nudge human behaviour rather than polish page layouts, performance transforms.
At Leopard Co, we call it behaviour-first marketing – because every click starts in the brain, not in the code. It’s an approach that blends behavioural science with creative, digital and communications strategy to help brands grow faster and connect more meaningfully with audiences.
We think users behave like Spock. They don’t.
Most marketers picture their customers gliding smoothly through an elegant, well-tested funnel – landing page, product, checkout, confirmation.
In reality, behaviour looks a lot more like a cat chasing a laser pointer.
Psychologist Daniel Kahneman described this as the battle between System 1 and System 2 thinking. System 1 is fast, emotional and intuitive – it’s Homer Simpson reaching for the doughnut. System 2 is slower, deliberate and analytical – Spock weighing up the logic.
CRO has spent too long designing for Spock. But 95 per cent of our decisions happen in Homer’s head. We buy on impulse, justify afterwards and move on.
Understanding that single truth changes everything.
CRO should optimise the decision, not the design
Traditional optimisation obsesses over pixels: button colour, call-to-action copy, image size. Those things matter, but they only affect what people see.
Behavioural science deals with what people feel – and that’s what shapes what they do. In applied marketing psychology, emotion isn’t a soft metric – it’s a measurable driver of performance across digital journeys and brand communications.
Every user journey follows the same human sequence:
See → Feel → Act.
The “feel” stage is where persuasion lives. Change the feeling, and you change the outcome.
If you’re new to this, our Behavioural Science service page is a good starting point. It explains how we combine behavioural frameworks with creative testing to improve both engagement and conversion.
Why biases belong in your CRO toolkit
We humans are cognitive misers. We use mental shortcuts – or heuristics – to save effort. At Leopard, we’ve mapped 35 common behavioural biases that influence how people think, click and buy. You don’t need to use them all, but a handful appear in nearly every experiment.
Scarcity – when things run out, we rush in
When supply is limited, demand spikes. That’s why “Only two left in stock” and “Offer ends midnight” still work decades after they were invented.
Scarcity has flavours:
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Time-bound scarcity creates urgency (flash sales).
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Quantity-bound scarcity creates value (limited editions).
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Social scarcity creates status (“Selling fast” or “Popular right now”).
The trick is to create momentum, not panic. Give users a reason to act now, not to abandon out of frustration.
The endowment effect – make it feel theirs before they buy
People value what feels like it already belongs to them. A personalised journey (“Your order”, “Your plan”, “Your space”) activates a subtle sense of ownership.
Even simple progress cues – “80 % complete – almost yours” – tap into this bias. Once we’ve invested effort, our brains resist the idea of giving it up. That sense of micro-commitment keeps people moving forward.
The labour illusion – show the work
Humans trust what looks like work. We prefer to see effort, even when it slows us down. Think of “Finding the best deal for you…” or “Checking availability…”. Those tiny moments of visible labour make us believe quality is being checked behind the scenes.
As one of our previous Leopard blogs on the principles of Behaviour Change put it: transparency builds trust, and trust builds conversion.
The COM-B model: why people click (and why they don’t)
Every behaviour can be broken down into three components: Motivation, Opportunity and Capability. For digital marketing and UX teams, the COM-B framework is a practical tool to diagnose why users hesitate, abandon or convert.
If motivation fades, people drop off.
If opportunity isn’t there (the context is wrong), they hesitate.
If capability feels low (too complex, hidden costs), they quit.
Research consistently shows:
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Around 70 % of online carts are abandoned – motivation fades mid-journey.
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Mobile conversion rates trail desktop by roughly 25 % – opportunity gap.
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Nearly half of shoppers leave when extra fees appear at checkout – capability failure.
The COM-B model gives CRO teams a lens to diagnose where and why users fall away. Fix the behavioural barrier, and design takes care of itself.
The EAST framework: how to design for instinct
Once you know what’s breaking behaviour, you can design interventions around it.
The EAST framework – Easy, Attractive, Social, Timely – helps turn insight into action.
Make it easy by removing friction and simplifying forms.
Make it attractive with emotional cues and clear rewards.
Make it social by showing proof, ratings or trends.
Make it timely by nudging at the moment of intent – the cart reminder, the back-in-stock alert, the payday offer.
It’s a deceptively simple tool that keeps experimentation human-centred.
Quick wins vs deep experiments
You can always test quick wins – button text, layout tweaks, microcopy. They give small lifts, fast.
But deep experiments, rooted in behavioural hypotheses, uncover why people behave the way they do.
A good deep test asks:
“If I reduce friction in motivation or capability, how does behaviour change?”
That’s the difference between optimising a page and understanding a person.
Emotional design and the System 1 advantage
Emotion isn’t fluffy. It’s efficient.
The IPA Databank and System1 research show emotional advertising delivers stronger long-term growth and higher short-term conversion.
When a digital experience evokes emotion – delight, confidence, anticipation – it embeds itself in memory. Memory drives automatic, System 1 choice. That’s why “feeling right” converts faster than “reading right.”
Test, learn, repeat
Behavioural CRO is a discipline of curiosity. Form a hypothesis, test it, measure real human change, then iterate.
Start small: pick one bias, one page, one measurable behaviour.
Use COM-B to find the friction, EAST to design the intervention, and emotional measurement to track impact.
Because in the end, CRO is just psychology, measured.
Funnels are fiction. Real journeys zig-zag through emotion, habit and instinct. When you design for behaviour – not just usability – you make digital experiences feel effortless and human.
FAQs
What exactly is behavioural science in marketing?
It’s the application of psychology and decision science to marketing and communications. Behavioural science helps brands understand how people think, feel and act – and then design strategies that make positive actions easy and instinctive. At Leopard Co, we combine it with creative and digital expertise to improve engagement, conversion and brand effectiveness. Learn more about how we use it at Leopard Co.
Isn’t using biases manipulative?
Not if it’s done ethically. You’re helping people make quicker, better decisions, not tricking them into choices they don’t want.
How can I get started?
Start with curiosity. Review your conversion funnel through a behavioural lens. Where do people hesitate? Which bias might explain it? Then design a small experiment around that insight.
If you enjoyed this article, explore more on How Emotion Drives Marketing Effectiveness or visit our Behavioural Science page to see how Leopard applies psychology to marketing performance. You can also read more about our insights on marketing effectiveness, UX psychology, and behavioural communications across our blog.