Suppose you want to quit smoking or lose weight, and you’re committed. We all know that this commitment can fade over weeks, when it gets hard. What if you’re really serious? What if you were so serious, you’re willing to handcuff yourself so that you can’t smoke again, or eat that doughnut?
A commitment device is anything that locks you into a plan of action that you don’t necessarily want to do. People have done this forever; for example by publicly saying you will do something, you might create expectation in others (or shame for yourself) if you fail to do it. Other people make bets with one another, and use money as a way to motivate themselves to make a change. (“I’ll bet you $100 I can quit smoking for a week”).

In the table above, you’ll notice how the negative motivator (what you lose if you don’t follow through) could be just about anything from money, to disappointing friends, to what will be in your pantry in the future. Back to Greek Myth, one of the earliest examples in literature was Odysseus encountering the sirens; knowing that he would fall victim to the siren’s song, he had his men bind him to the mast of the ship so that he could not leave the ship.

Supposedly, the more costly the outcome if you don’t do what you’re supposed to, the more motivating it is. Some have even gone as far as to write big checks to causes they despise (for example, the opposing political party’s candidate) — and instruct a friend to mail the check if they didn’t achieve a goal in a fixed period of time.
How They Work
- They divide our internal selves into two halves, which are fighting: the part that knows you need to quit smoking (“the head”) and the part that wants to smoke (“the heart”)
- They divide ourselves again into two halves, present and future, which is referred to as time inconsistency.
- The one half sets out to conquer the other, by planning ahead. The head tries to get the upper hand on the heart by creating costs and laying traps.
I think this is a generally fair description of how they work in terms of internal psychology; I’m fairly uncomfortable with the underlying assumptions here that there really are two selves within each person, I suspect that is not right. But it is a very popular view, and does drive how these devices work.
Do they actually work?
Sometimes yes, sometimes no. “Device” is the perfect word here; they probably work about as well as the device is designed.
One reason why is that the penalty is usually to the head; maybe you lose some money. But does the part that wants to smoke care about that? Another reason is that they still require will power and tend to focus on that as the method of control of the self. In another post, we’ve discussed extensively why will power isn’t the way. Likely the biggest way commitment devices fail is that very few people adopt them in the first place. A lot of people toy with the idea, but the AMA’s survey on the topic has indicated that uptake is very low, even among those who know they might help.
Finally – “losing” on a commitment contract can be very demotivating. For example, some alcoholics may take disulfiram to make them ill if they drink; if they nonetheless still took a drink, it’s important to think about whether that properly motivates the next round of effort.
Still, they are very attractive. So much so that there is an entire internet platform called StickK which allows people to sign up and bet money against themselves for exactly this purpose. They can be made more effective too with some tweaks, like incorporating a social element (for example online, with friends). Public accountability is emotionally impactful in a way that losing $20 isn’t. It is also possible to engineer them to include positive reinforcements, and not just negative.
In short, they can work, but need to be properly designed.
References
- Commitment Devices
- Bestiary of Behavioral Economics: Commitment Devices
- Stanford Encyclopedia of Philosophy: Dualism
- Harvard University: Todd Rogers: Commitment Devices
- StickK.com