1.5 Minutes on Influence: The Swimmer’s Body Illusion and Making Others Feel Important

Happy 1,5 Minutes on Influence!

Here is your weekly dose of applying the psychology of influence
to positively impact choices and behaviours.

Looking forward to sharing insights with you!

Warm regards,



I don’t know about you, but now that the summer holidays are around the corner, I become very aware of my physique. That’s why this week, I want to introduce you to the so-called Swimmer’s Body Illusion. And it might surprise you: it’s not just about looking lean and fit when you parade down the beach. It has everything to do with shaping choice and influencing behaviour.

The Swimmer’s Body Illusion is a nugget of wisdom from Nassim Taleb, author of The Black Swan. Once, he decided to shed the extra weight he had gained. He had always admired the physiques of swimmers, with their well-built and streamlined bodies. So, he thought it was simple: he would take up swimming.

However, he soon realized he had fallen for a misconception. Professional swimmers don’t have perfect physiques because they train extensively; rather, they are good swimmers because of their physiques. The appealing look of their bodies is a selection factor, not a result of their training.

So, how is this relevant when you are trying to influence choice and behaviour?

Well, as professionals, we often focus on results. Can we get clients to join us? Can we get people to act more sustainably? Can we get someone to take preventive care of their health? And so on. The challenge with many desired outcomes is that they lie in the distant future. As a result, we often try to influence future-oriented decisions. However, we frequently overlook the selection factors that influence these decisions.

Present bias is one of these factors—it’s the tendency to prioritise short-term gains over long-term success. But it’s not the only one. Other examples of factors are social norms, perceived risk, emotional triggers, ease of access, personal values and beliefs, or perceived control.

People tend to make choices based on immediate influences. That’s why our efforts in trying to convince people to do something for their future benefit often fail.

So, what can you do?

Instead of trying to convince someone of something that will benefit them in the future, focus on the underlying selection factors. Or, as we Behavioural Designers put it:

Create a context that naturally aligns with long-term benefits and helps people make better choices effortlessly right here and now.

For example, by designing default options that favour long-term well-being, leveraging social proof, ensuring convenient access to healthy choices, or addressing emotional triggers.

To conclude, next time you’re working on a behavioural intervention, remember Taleb’s Swimmer’s Body Illusion. Focus on the selection factors – the conditions and contexts that shape our choices and behaviours – rather than just the results. This shift can lead to more effective and sustainable behavioural change.

Until next time! Keep thinking about the factors and enjoy catching some of that vitamin D.

PS. And the next time you feel intimidated by an overly athletic swimmer, remember that they were probably born with that physique—no amount of training we could have done would have achieved it. What a relief!


Are you a forward-thinker?

We have translated the most groundbreaking insights from the psychology of influence into practical methods and tools. We teach these in our two-day Behavioural Design Fundamentals Course. You can download the brochure here NL and UK. The training is available in both Dutch and English, and can be tailored for teams. But it is especially suited for forward-thinkers.


The Importance of Importance

This week, I want to end with a powerful quote with you by business woman Mary Kay Ash, who at her death had a fortune of 98 million dollars:

It’s so simple, yet makes such a difference. Pretend that every single person you meet has a sign around his or her neck that says, ‘Make me feel important.‘”

Imagine the impact this could have on your interactions. Whether you’re talking to clients, colleagues, or friends, this mindset can transform your relationships. Acknowledging and valuing others makes them feel important and appreciated, which can lead to more meaningful connections and positive outcomes.

Give it a try this week—see how making others feel important can make a big difference in your professional and personal life.




Until next week,
Astrid Groenewegen

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