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Phil Agnew
Square in your ship's path are sirens crying beauty to bewitch men coasting by. Woe to the innocent who hears that sound. Sirens will sing his mind away on their sweet meadow lolling. There are bones of dead men rotting in a pile beside them and flayed skins shrivel around the spot. Steer wide, keep well to seaward. Plug your oarsmen's in ears with beeswax kneaded soft. That's the warning given to Odysseus in Homer's famous tale. To correctly navigate his ship, Odysseus does something remarkable. He doesn't trust his own willpower. He knows that the moment he hears the siren's song, he'll want to follow it. So he removes his choice entirely. He orders his crew to stuff their ears with wax and then has the crew lash him to the mast. He'll hear everything. He'll beg to head towards the sirens. But his men have orders to ignore him and keep rowing past the island.
Owen Service
That metaphor of Odysseus, you know the figure from the Odyssey is now, as you'll know, is now used by behavioral economists to sort of think about commitment devices in general.
Phil Agnew
Odysseus used what we now call a commitment device. He didn't trust his own willpower. He locked himself into a decision which his future self couldn't undo. Today on Nudge, we will cover commitment devices, explaining how they can help you exercise, save and even stay with your partner. All of that coming up. When someone asks AI for a solution, a product, a service like yours, does your business come up? Does AI suggest you? Well, most companies have no idea and by the time they find out, they've already lost the deal or the sale to someone who did. HubSpot AEO helps you show up in those moments with the right answers buyers are looking for before the first click and before the first form is filled out. That's the moment HubSpot A E O is built for. Check out HubSpot.com, the agentic customer platform for growing businesses. Hello, you are listening to Nudge Podcast with me, Phil Agnew. Today on Nudge. I'm delighted to welcome to the show Owen Service.
Owen Service
I'm Owen Service. I'm the CEO of a company called Cogco. We work with organizations who want to understand their customers, their employees in a previous life. And I think a lot of this discussion is going to touch on this. I was one of the co founders and the managing director of the behavioral Insights team, the so called Nudge Unit. I'm an Honorary professor of Behavioral Science at Warwick University. Before that I. I was a Deputy Director of the. The Prime Minister's Strategy Unit.
Phil Agnew
Alongside that impressive career, Owen has also found the time to write one of my favourite books, Think Small.
Owen Service
I wrote it with my old colleague Rory Gallagher when we were at the Behavioral Insights Team together. We, we kept on getting asked this question, which is all around the fact that most of our work back then, or all of our work was on how you could change policy to encourage citizens to do the right thing in relation to paying their taxes or searching for a job, for example. And people kept on asking us, like, can you use these same ideas and apply them to yourselves to help you to achieve goals that you might have in your personal lives?
Phil Agnew
Well, yes, you can use those same ideas in your personal life. At least that's what Owen and Rory propose in the book. And arguably the most powerful way we can use behavioral science in our personal lives is by using these commitment devices. These are small nudges that commit us to a future behavior. Here's why commitment devices are so important.
Owen Service
We have two competing selves when it comes to thinking about what we might do. We have our present selves and our future selves. And they're often in competition with each other, or at least see the world slightly differently, right? So our present self typically enjoys ice cream and relaxation, and future cells typically prefer salad, brown rice and exercise. So, you know, this is sort of encapsulated with the notion of going to the gym. And most people will think, yeah, I'll go to the gym, but I'll do that tomorrow. Our present self likes to chill, and it will defer that decision to our future self. The challenge, of course, comes with the fact that by tomorrow, when tomorrow comes, it's actually your present self that's taking the decision. And a lot of the time, your present self will then defer that decision again till tomorrow and so on.
Phil Agnew
To overcome the inherent laziness of the present self, we can use commitment devices.
Owen Service
And what a commitment devices is designed to do is to bind that future self to action, such that when your present self is at that future moment in time when it might wish to defer that action to another moment in the future, it feels the need to be consistent with that upfront, upfront pledge.
Phil Agnew
So rather than trying to stop eating chocolate every day, you can just remove chocolate from your kitchen. Rather than saying you'll donate to charity. Next time you see a donation box, you. You can just set up a monthly direct debit. These commitments lock us to a future behavior. And Owen's co author Rory has used these devices in the past to help job seekers find work.
Owen Service
Rory led a big program of work with UK job centers. The individuals in those job centers were making commitments to undertaking particular actions through the course of their lives. So, for example, you might pledge to undertake some work on your on your cv, but instead of just saying, yeah, I'm going to do this, you would commit to undertaking work, say on your CV after you've had your breakfast, for example, on a Tuesday morning. And what an implementation intention is designed to do is to create a cognitive link between the action that you want to undertake working on your CV and that specific future moment in time. And that makes it more likely that you'll ultimately follow through on your commitment.
Phil Agnew
In the book, Owen explains that the job seeker advisors would use these commitment contracts where the job seekers pledged to complete them before the next meeting. These pledges could be working on a cv, making applications for jobs and buying new tools to help them prepare for the jobs the jobseeker was applying for. The commitment device was tested in a six month randomised controlled trial at a job Centre plus location in Essex. The results were striking. Job seekers in the treatment group were 15 to 20% more likely to be off benefits and working 13 weeks after signing on. It's fascinating. Simply making a public pledge to complete a task made people far more likely to complete that task. Owen and Rory weren't the first to discover this, of course. Way back in 1997, two German researchers mischievously asked their students to write a university assignment on Christmas Eve, a day where none of their students would really want to work. The students were asked to describe exactly how they felt at the time and how much it met their idea of pleasant leisure. They were to complete these reports during the Christmas break on Christmas Eve to ensure that their memories remained as vivid as possible. The researchers deliberately chose this assignment because it was awkward enough to guarantee a low base rate of completion. However, half of the students were asked to create a commitment device stating when and where they intended to sit down and start writing. For example, one of the students said that they would do the assignment straight after church on Sunday at their father's desk. Turns out those who created a commitment device were more than twice as likely to complete the task within the specified time period as those who had not. However, it is not just applications and university essays. Commitment devices can be used for all sorts of personal goals.
Owen Service
We used a particularly strong form of commitment device to encourage Rory to get more fit and active Rory decided he
Phil Agnew
needed to go to the gym at least twice a week. Given that he'd failed to go to the gym more than a handful of times in the previous year, this felt like a stretch. To help, he commandeered the Behavioral Insights Team whiteboard, which at the time was located on a wall in the middle of the office. On it, Rory wrote his commitment on the board. He said, I will go to the gym twice a week for three months. By writing down his commitment and displaying it publicly, Rory knew that he would feel this strong sense of duty to remain consistent with his pledge. Much of Rory and Owen's ideas are inspired by Katie Milkman's work on these commitment devices, including one study where Katie Milkman encouraged employ to get vaccinated.
Owen Service
And what she effectively found was that if you told somebody that they were booked into getting an influenza vaccine which was provided through an employer, they were more likely to show up. If you encouraged an employee to write down when they would go. So specifically the date and the time that they would show up. She saw 13% increase in vaccine take up when you got somebody to write down when and where they were going to get vaccinated.
Phil Agnew
In Katie Milkman's studies, the 3,300 employees had to write down exactly when they planned to get vaccinated. And writing down a commitment seems to make us far more likely to stick with that commitment. It's an effect Owen has seen in studies from way back in the 1950s.
Owen Service
So actually, one of my favorite examples goes Back to the 1950s, the work of Solomon Asch, who is a psychologist. He was particularly interested in why it was people would obey orders in positions of authority in the aftermath of the Second World War. And he devised these really neat studies that involved showing people lines on a card.
Phil Agnew
I've spoken about this before. People in these studies pick the obviously wrong answer only if others in the group had already picked the wrong answer before. Then let's explain it for you. We can do an example. So, for example, I'm going to ask you which of these beeps is longer? You know it is the second beep. It's obvious, right? But if you were asked in a group setting and lots of other participants publicly declared first that the first beep was longer, well, then many of you would pick that first beep rather than the second beep. In the study, 37% of participants picked the wrong beep. At least that is what Solomon Asch found in the 1950s. Interestingly, Professor Richard Wiseman recently told me that it is hard to replicate these studies because conformity is less commonplace nowadays. It was far more commonplace after World War II. Nevertheless, Asch devised a way to stop these people giving the incorrect answer when others in the group did. He got them to use a commitment device.
Owen Service
When you ask individuals to write down what they think the answer is before anybody else has intervened, it almost eliminates that problem because you have that tendency, that desire, to be consistent with your own stated beliefs and opinions.
Phil Agnew
When the judgments were written down in advance on a piece of paper, the errors were hugely reduced by more than three quarters. We are influenced by the crowd unless we privately write down our opinions. Owen sees this all the time in work meetings.
Owen Service
And the reason I like that example is that when you're in a meeting with colleagues and somebody is asked their opinion, especially if it's a relatively senior colleague who offers their views first, a lot of the time you will find that other people within that meeting, meeting will come in behind and agree with that initially stated view. But if you get people to write down their opinions in advance of that individual stating their opinion, you will find you get a much wider range of views being asserted.
Phil Agnew
People stick with an opinion if they commit to it in advance, if they write down their commitment, like Katie Milkman's vaccinated employees, or if they state it publicly, like Rory and his whiteboard commitment to exercise. And in fact, Owen shares evidence which suggests that married couples are more likely to stick with their vows of staying together if they make their commitment in front of a large audience.
Owen Service
It's difficult to run a fully randomized controlled trial when it comes to wedding vows. You can't say, well, we're going to get 1000 of you to commit in this way and 1000 of you to elope and see what difference that makes in practice. So a lot of the, the work in there is, like, relatively anecdotal. But what it does seem to show is that there is a correlation between the number of people that you have in your wedding and the chances of you not getting divorced.
Phil Agnew
Randy olson, in his 2014 analysis, found that couples who elope are 12 times more likely to end up divorced than couples who get married at a wedding ceremony with 200 people. In fact, just having one guest at your wedding makes you 35% less likely to get a divorce than those with no guests. 11 guests. And there's a 56% chance you'll stay together. 51 guests. And there's a 69% chance the married couple will be together. Owen does caveat this. He writes that there are, of course, many confounding factors at play here. It may well be that couples who get married on their own are more likely to be doing so impulsively. Nevertheless, this is strongly consistent with other work which suggests that making your commitment public in front of a group of family and friends may provide you with the motivation and networks needed to make you more likely to stick together. For better or worse. Commitment devices keep us exercising for longer, saving more often, and even more independently minded. But that's not all. After the break, Owen shares how a commitment device encouraged students to watch critically acclaimed movies over rom com. Rubbish. The podcast I'd like to recommend today, after you listen to Nudge is Billion Dollar Moves, hosted by Sarah Chen Spellings and is brought to you, of course, by the HubSpot Podcast Network, the audio destination for business professionals. Listen and you will hear Sarah ask the hard questions and uncover these triumphs, failures and lessons from the top business leaders, all so you can make your own billion dollar moves in venture, business and life. It's a wonderful podcast. So go and listen to Billion Dollar Moves wherever you get your podcasts. Hello and welcome back. You are listening to Nudge and I must say thank you for listening to Nudge. There is an awful lot of easy to listen to podcasts out there on sport, on comedy, on reality tv, but you are choosing to listen to something that hopefully you find a little bit educating. Some might even call this podcast highbrow. I wouldn't, but maybe some would. Not everyone has the intellectual qualities of you. Some struggle to watch and listen to anything cognitively stimulating. But in 1999, three researchers ran a study to help students pick high brow movies over low brow ones.
Owen Service
So yeah, so it's actually a, it was a study was led by Daniel Reed at Warwick alongside George Lowenstein and Shabana Kalyamaran. Yeah, they, they like a lot of, a lot of researchers enjoyed conducting studies using their students. What they did in a study was they got two groups of students and they said great news, we're gonna let you watch some, some films and you can choose what films you wanna watch. But there was a twist as ever. In the first group they got them to choose a film every day that they got together. They did this every night for three days and they got to choose from this collection of films which were divided into highbrow films. I think in the study they had this central observation which is that everybody at the time was saying that they really wanted to watch Schindler's List but hadn't quite got round to doing so and tended to end up watching Batman vs Superman instead. That was their example of the exemplar of low brow versus highbrow. And so the first group, yeah, they got, they got to choose a film from this collection of highbrow and low brow films every day. But importantly, they would choose the film on the day, each day. And in the second group, exactly the same setup, but instead of choosing the film every day, they would choose all three films on the first day. Going back to what I was saying about your present self having different preferences to your future self, the idea was that, or the hypothesis was that maybe your future self would be more inclined to watch highbrow films than your present self. And that was exactly what they found. They found that whenever you got somebody, a group of students to choose what film they wanted to watch in the moment, they would choose a low brow film. Right? So at the moment it might be, you know, do you want to watch tonight we're going to choose a film. Do you want to watch Hamnet? Or do you want to watch Happy Gilmour 2? And if it was now in the moment, you might well choose Happy Gilmore 2. But they found that when people were making choices about what they wanted to watch tomorrow, they'd be much more likely to choose HAMNER OVER Happy Gilmore 2.
Phil Agnew
This study, run on 77 participants at the University of Illinois, found that students were 37% more likely to watch highbrow films like Schindler's List, the Piano, or subtitled European Cinema. If they had picked those films in advance, if they were to pick the films on the day, they were much more likely to watch lowbrow films like Speed, Mrs. Doubtfire and four Weddings.
Owen Service
And interestingly, in that group of people who got to choose what the next two films would be, on the first day, they chose the lowbrow film. And on the second and the third day, it was the highbrow film.
Phil Agnew
And Owen says, you can test this out on your colleagues.
Owen Service
I know Daniel Reed has done various other studies that are similar in design to this. So one example that your listeners can all try themselves is that if you get people to choose what kind of snacks they want to have for the meeting next week, you tend to find that people are much more likely to choose fruit and nuts than chocolate and sweets. If you just ask people what you want to have now in the meeting, right now, it's biscuits and sweets all around.
Phil Agnew
Commitment devices work for healthy eating, for exercise, for picking quality movies and sticking with your partner. But Owen, in his book Shares one more commitment device example. In fact, he calls it his favorite example.
Owen Service
This is a study that was led by Nava Ashraf, who I think now is at the London School of Economics. And she at the time was doing some work with researchers, including Dean Carlin, who's done a lot of work in this exact area around how to set and achieve goals. They were working on a savings product with a bank in the Philippines and the bank was trying to encourage people to stick to saving more. It was a relatively complex study because they couldn't force anybody down the path of making a binding commitment. So what they did instead was they identified a large number of people who might potentially benefit from saving more and they offered all of them the chance to open either a standard savings account or a commitment based savings account. Importantly, all of the elements of the accounts, like the interest rate, for example, was the same for both of these accounts. The only difference was that the commitment device account required you to make a binding commitment to achieving a savings goal.
Phil Agnew
The savers could either decide to set a goal that was linked to a large sum of money that was needed to save, for example, Christmas, or saving money for school, or they could just set a goal which was linked to a set amount of money they needed to save, for example, I want to save £1,000. They had complete flexibility over what the goal might be. But, but once the goal was set, it was explained that the commitment would be binding. In other words, they would only receive the money if they met their target or once they reached their target date.
Owen Service
I mean, the first sort of interesting observation is that about 30% of people said that they would prefer the commitment account even though the interest rate was the same. And it had, it came with this string attached, which is that you couldn't get your money out until you'd achieved the goal. And what they found was that if you opened a commitment based account, you saved much more than if you just had a standard Savings account.
Phil Agnew
After 12 months, the researchers measured the average bank account savings of those who had been offered the commitment accounts relative to a control group of people who had not. And they found that the average saving balances increased by 81% for those who had used the commitment device accounts. The name of this paper links back to the story shared right at the start of today's episode.
Owen Service
And they called the paper tying Odysseus to the mast.
Phil Agnew
Turns out we are similar to Odysseus. We are better at sticking to our goals if we make a binding commitment to do so.
Owen Service
You see, people doing this in one way or another all of the time. I myself use commitment devices a lot. One of the most basic commitment devices that you can make is if, like me, you know that you should exercise but you struggle to go out for a run is to sign up to an event in the future that will require you to undertake some training in order to to do it. So every year, for example, for the past six or seven years, I have signed up to the Ealing Half Marathon which I would encourage all of your your listeners to to to join me for. It's a great community event. I really enjoy having done a run, but I hate actually doing running. So I use the annual Ealing Half Marathon as a personal commitment device. What I find is that through the course of the spring and the summer it forces me to get out and to train. Knowing that this event is coming up at the end of September, Owen doesn't
Phil Agnew
trust his own willpower to guarantee he exercises. He makes a commitment to run the Ealing half. This financial and public commitment makes him more likely to run and you can do the same. Following the simple tips laid out in today's show. Writing down when and where you'll do something will double the chances that you'll follow through of it. Making a commitment public makes you more likely to keep it. The bigger the audience when you make your commitment, the harder it is to back out. Choose in advance rather than on the day and binding financial commitments will increase savings by 81%. But Owen and I were not done there.
Owen Service
I think it remains one of the most powerful get out to vote initiatives that's being conducted.
Phil Agnew
To hear that study the psychology of peer pressure and the strategies used by some of the fastest growing fitness companies. You'll have to listen to the next episode of Nudge to make sure you don't miss that. Go and subscribe to Nudge wherever you get your podcasts and sign up to our newsletter. Head to nudgepodcast.com and click Newsletter in the menu. If you do, you'll get an email as soon as the next episode is live. Massive. Massive. Thank you to the brilliant Owen service for coming on the show. A link to his fantastic book is in the show notes and there you will also find links to the wonderful work he and his team does at Cog company. I'll be back next Monday and Owen will be joining me back again on Nudge in a few weeks time. Cheers.
Episode: Why Willpower Alone Doesn’t Work
Host: Phill Agnew
Guest: Owen Service (CEO, Cogco; Honorary Professor of Behavioral Science, Warwick University; Co-author of "Think Small")
Date: May 4, 2026
This episode explores why relying on willpower alone isn’t effective for achieving personal or behavioral goals. Instead, it delves into the power of commitment devices—psychological tools and strategies that lock us into desired behaviors, helping us “nudge” ourselves towards the outcomes we truly want, even when our immediate impulses would drive us off course. Phill and Owen unpack classic research and practical examples on how these tools work across exercise, savings, job seeking, relationships, and beyond.
“He doesn’t trust his own willpower. He knows that the moment he hears the siren's song, he'll want to follow it. So he removes his choice entirely.” — Phill Agnew, 00:37
Owen’s Background and the Birth of "Think Small" (02:25)
Why Commitment Devices Work
“Our present self typically enjoys ice cream and relaxation, and future cells typically prefer salad, brown rice and exercise.” — Owen Service, 03:56
Jobseeker Example (UK Job Centres, RCT):
“She saw 13% increase in vaccine take up when you got somebody to write down when and where they were going to get vaccinated.” — Owen Service, 09:22
“There is a correlation between the number of people that you have in your wedding and the chances of you not getting divorced.” — Owen Service, 13:15
“They found that when people were making choices about what they wanted to watch tomorrow, they'd be much more likely to choose HAMNER over Happy Gilmore 2.” — Owen Service, 17:48
“If you opened a commitment-based account, you saved much more than if you just had a standard Savings account.” — Owen Service, 21:27
“I really enjoy having done a run, but I hate actually doing running. So I use the annual Ealing Half Marathon as a personal commitment device.” — Owen Service, 22:57
Key Strategies Mentioned:
Phill and Owen convincingly argue that willpower alone is a poor tool for change. Instead, practical, evidence-based commitment devices—public pledges, pre-commitment, automation, and specificity—can transform intentions into sustained action across many areas of life. Like Odysseus, we’re best off when we “tie ourselves to the mast” and make it hard to backslide on our best-laid plans.
For more “nudges” and behavioral science insights, subscribe to the Nudge Podcast or check out Owen Service’s book "Think Small" and his work at Cogco.