Decisions, decisions, decisions… Why people join a clinical trial?

To understand why people decide to take part in clinical trials, you first need to understand how people make decisions. Let’s try an example first. Give yourself about 20 seconds to read and answer the following question:

If a lily pad patch doubles in size every day, and it covers the entire lake in 48 days, how long will it take the lily pad patch to cover half of the lake?

Your first gut instinct is to say 24, right? After a bit of thinking, you can work out that the answer is actually 47. But that first gut instinct is interesting, isn’t it? Why do we do that?

The same thing goes for interacting with posts on social media. And we’re not talking about liking your friend’s posts here, we’re talking about interacting with brands. What made you like their post? Or visit their website? Or even buy their product? The likelihood is that their content sparked a subconscious emotional reaction and that’s what caused you to want to take action.


The science behind emotional connections

There’s actually a tonne of science behind why we make decisions based on emotional connections. This is called behavioural science, and it helps us to understand why we make decisions in the way we do.

Did you know that we make an average of 35,000 decisions every single day?

There’s no way that we can use our rational thought, energy and attention on every single one of those decisions, so something has to simplify our decision process. As humans, we have the capability to think both fast and slow. This is what we showed you with the lily pad question - the likelihood is that you had the initial answer of 24, then moved onto 47 once you’d thought about the question more carefully, right? This is a great example of what’s called dual processing, the official term for gut thinking and conscious thought. Here’s the differences between the two:


System 1: Gut feeling

System 2: Conscious thought

Fast, effortless and uncontrolled

Slow, effortful and controlled

subconscious, automatic and intuitive

Conscious, reflective and rational

Based on emotions and feelings

Cognitive and calculating


Thanks to the effortlessness of our gut feeling thinking, we can make decisions in a heartbeat. In fact, we actually make decisions before we’ve even realised. Researchers studying this phenomenon of unconscious decision making are able to predict decisions based on brain activity, and can correctly predict which choice people would make 7-10 seconds before they were even aware they had made a decision.


So… how does this help clinical trial recruitment?

In simple terms, we advertise clinical trials and attempt to get people to decide to take part. We advertise, cause a reaction, and get people to act. As you might have expected, there are ways that advertising can make the most of these gut-feeling, decision-making behaviours.

Research has found that campaigns with more emotional appeal tend to perform better than those including rational thinking. In fact, campaigns with purely emotional content performed nearly twice as well as the rational ones. This definitely translates over to clinical trial recruitment, patient facing materials in clinical trials that show true emotion and empathy are much more relatable for patients. You’ll often find that patients volunteer for altruistic reasons, and there’s plenty of research that shows the relationship between empathy and a greater motivation to perform altruistic acts.

So how can we use the psychology of decision-making to enhance patient recruitment? Through displaying empathy and using relatable emotions in patient recruitment materials, we are more likely to tap into the patients’ ‘gut feeling’ thinking, helping to increase our chances of recruiting them.

If you enjoyed learning about the psychology of decisions, you’d also probably like these tips to help increase patient recruitment and retention using behavioural psychology. If you’d like to talk to us directly, drop us an email at — we’d love to chat.

Patient Recruitment

Maddi Needham

Maddi describes herself as ‘a little nosey’ – which is just what makes her excel in the research she does for us. Her positive energy and get-up-and-go attitude help make every project a success, understanding patients’ needs on a more fundamental level.

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