Forcing Function

What it is

The distinction that justifies a separate page is between the environmental and the contractual. A forcing function arranges the world so that the alternative is absent, costly or impossible, and it holds whether or not you agreed to anything. A precommitment binds your later self by an agreement, a payment or a declaration, and it holds because you are unwilling or unable to break your own terms. The same goal can be pursued either way and the failure modes differ. A contract can be renegotiated by the person who signed it. A wall cannot be argued with.

The best specimen this publication has met is a clock. The F-16 retains a small hand-wound analogue clock from its 1970s design, and Air Force instructors teach that before making a decision in an emergency you wind it. It takes a few seconds, it occupies both hands, and while it is happening you physically cannot touch anything else. Nobody agreed to anything and there is no contract to renegotiate under stress, because the constraint is a property of the object and of where your hands are. A rule saying pause before acting is advice, and it gets ignored by exactly the person who most needs it. A clock that has to be wound is not advice.

The failure it defends against is well documented. Air France 447 was level at cruising altitude with no mechanical malfunction, and the crew would have flown on untroubled had nobody touched anything for a few minutes.

In effect

In behaviour-change writing the device usually appears in weaker forms, and the weakening is instructive.

A deadline imposed by somebody else is the cleanest version, because the person subject to it cannot lift it. Benjamin Hardy tells the story of the pastry chef Christina Tosi being given three hours by David Chang to produce a dessert she would not otherwise have attempted, with Chang saying he had to push her off a cliff because she would not do it herself.

His own example is a price-based commitment, not a forcing function: he and a friend paid several hundred dollars to enter an endurance race before training for it. He names the sunk cost fallacy explicitly and inverts it, arguing that a bias usually described as an error can be turned into a motivational device. But he could have forfeited the money at any point, which makes it contractual, and the account does not distinguish the two.

The claims attached to that story are his own and should not be carried further: that financial investment produces enhanced imagination, and that the payment set off a cascade through several unrelated habits. Single case, self-reported, retrospective, no measurement and no comparison. Parkinson's law is invoked alongside as though it were a law.

What it does not say

It does not have a study behind it in the popular sources. Nobody is credited on the pages where it appears, and the nearest established home for the phrase is the design literature on constraints, where a forcing function is a designed impossibility rather than a motivational technique.

It does not mean a commitment device generally. Merging it with precommitment loses the one property that makes it reliable, which is that there is nothing left to negotiate with.

It does not produce the downstream cascades claimed for it. Those are one person's retrospective account of their own life.

And it does not always survive contact with a determined person. A constraint that can be removed by the person it constrains is a contract wearing a wall's clothing, and it should be described as the former.

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