If-Then Plans

Why good intentions so often stall, what the research on if-then plans shows, how to write one that holds, and how to use one to change a habit you already have

11 minute read  ·  2,386 words

You decided on Sunday evening that this would be the week you went for a run before work. Monday came, the alarm went off, it was raining a little, and there was an email you wanted to answer first. By Thursday the plan had somehow become next week’s plan.

None of that means you didn’t want to run (unless you’re like me, in which case you definitely didn’t. I’d only run if something was chasing me). Wanting something and doing it are two separate steps, and the second one happens at a particular moment, on a particular morning, when you’re tired, distracted or simply busy with something else. A good intention often doesn’t fail because it was weak. It fails because nobody decided in advance what would happen in that moment.

An if-then plan is a way of making that decision early. It’s a single sentence, it takes about a minute to write, and it’s one of the most studied tools in the psychology of behavior change.

Psychologists call this the intention-behavior gap, and it’s bigger than most of us would guess. When researchers pulled together dozens of experiments that had managed to make people more motivated, behavior did change, but only about half as much as motivation did.

So getting more motivated helps. Motivation on its own just leaves a lot of good intentions stranded between the decision and the action.

The psychologist Peter GollwitzerPeter GollwitzerGerman psychologist at New York University and the University of Konstanz who introduced the idea of implementation intentions, the if-then plans this article is about. spent much of his career on that stranded stretch. He noticed two kinds of intention. A goal intention names what you want: I intend to exercise more, to call my sister more often, to stop checking my phone at dinner. An implementation intention names when, where and how you’ll act on it, and it has a very particular shape:

The goal stays the same. What the plan adds is a moment and an action that are already chosen, so that when the moment comes, there’s nothing left to decide.

The decision has already been made

Many of the choices that derail a plan get made at the worst possible time: at the end of a long day, when something more pleasant is on offer, or when the moment slips past before you notice it’s arrived. An if-then plan moves the decision to a calmer moment, when you’re thinking clearly about what you want. Your later self no longer has to weigh up whether to act, only to notice that the moment has come.

The situation becomes a cue

Once you’ve decided “when I pour my first coffee”, the coffee starts to catch your eye. The moment you’ve named gets easier to spot, and it comes already tied to what you chose to do. When it arrives, the action tends to start with less effort, in a way that resembles a habit, even though it was set up in a minute rather than learned over months.

This is also why the “if” matters as much as the “then”. A plan attached to a clear, recognizable moment has something to be triggered by. A plan attached to “sometime this week” doesn’t.

What the studies found

The early studies were small, but their results were striking. In one, students agreed to write about their Christmas Eve in the two days after it. Of the students who sent one in, seven in ten of those who’d decided exactly when and where to write did it in time. Without that step, three in ten did.

In another, students were asked to exercise for twenty minutes in the following week. Information alone changed nothing: about a third exercised, just like the students who got no information at all. Of those who also wrote down when and where, nine in ten did!

Out in the real world the effect is smaller. At one large company, adding a single line to a flu vaccination letter, asking people to write down the date and time they’d go, got about four more people in every hundred vaccinated. Results elsewhere have been mixed. The largest review so far, of 642 tests, sums it up well: if-then plans help with actions, thoughts and feelings, and their effect on everyday behavior is small but reliable.

It works for harder goals too

It’s fair to wonder whether something this simple only works for people who were going to manage anyway. A review of 29 experiments with people who had a mental health condition, or high levels of symptoms, found that forming if-then plans helped them reach their goals across different conditions and different kinds of goal. The average effect was large, though the results varied a lot from study to study.

It helps with feelings as well as actions. In one trial, people using an anxiety self-help book who also made if-then plans were far less likely to still be in the anxious range two months later than people using the book alone. In lab studies, a plan like “if I see a spider, then I’ll stay calm and relaxed” reduced fear, where the goal on its own didn’t.

Start with something you actually want

An if-then plan is a way of carrying out a goal, not a way of creating one. Researchers found that if-then plans helped people reach goals they genuinely wanted, and made little difference to goals they didn’t. If a plan keeps failing, ask yourself whether you want the goal or only feel you ought to.

Make the “if” specific

The most useful cues are ones you’ll reliably notice. A time works well: at seven on weekdays. So does a place: when I walk into the kitchen. Everyday routines make good cues too, such as pouring your first coffee, sitting down at your desk or locking the front door on the way out. The clearer the moment, the easier it is to recognize when it arrives.

Make the “then” small and concrete

The action should be something you could start within a minute of the cue. “Then I’ll exercise” leaves a lot still to decide. “Then I’ll put on my running shoes and walk out of the door” doesn’t. It’s fine if the first step is only the first step. The plan’s job is to get you started, because that first minute is where most good intentions stall.

Plan for the obstacle, not only the goal

The psychologist Gabriele OettingenGabriele OettingenGerman psychologist at New York University and Zeppelin University who studies how people think about the future. She developed mental contrasting and the WOOP method. added one step before the plan: picture the outcome you want, then honestly name what’s most likely to get in the way. The plan is then written for the obstacle: if it’s raining at seven, then I’ll do twenty minutes of exercise at home instead. If I feel too tired after work, then I’ll go for ten minutes and decide after that.

She called this mental contrasting with implementation intentions, and it’s often taught as WOOP: wish, outcome, obstacle, plan. A review of 21 studies found it helped people reach their goals, with a small-to-moderate effect. In one trial, women who learned it were about twice as active as women who only got information, nearly an hour more a week, and they kept it up for four months.

Make one or two, not ten

It can be tempting to write a plan for every goal at once. In one set of studies, planning helped people with a single goal, but when they planned for several goals at the same time, the plans stopped helping, partly because listing all the steps made the whole project feel harder. Start with the one plan that matters most this week, and add another once it’s become ordinary. If you’re not sure which one that is, sorting what’s urgent from what’s important can help.

Say it to yourself once

Writing the plan down is fine, but in the research it wasn’t what made the difference. Saying it over to yourself, even once, is what went with stronger results, so the link between the moment and the action starts to feel familiar. It also combines well with other tools. In a 2025 trial of worry postponement, people who added a plan like “if I notice I’m worrying before six, I’ll write it down and save it for worry time” worried for about fifteen minutes less a day than people who postponed without one, though it was a small first trial.

Give the old cue a new response

The same shape works for habits you’d like to break. Instead of naming a moment to start something new, the plan names the moment the old habit usually takes over, and gives that moment a different response. If I reach for my phone in bed, then I’ll put it on the chest of drawers across the room. If I want a snack while I’m working, then I’ll get a glass of water first.

Researchers have looked at what a plan like this does in the mind. Normally, when the familiar situation arrives, the old response comes to mind before any alternative. Forming an if-then plan took away that head start. The new response didn’t become automatic straight away, though. The plan gave people a real choice in the moment, and whether they acted differently depended on how much they wanted the alternative.

Say what you’ll do, not what you won’t

One kind of plan can backfire. A plan like “if I’m stressed, then I won’t eat chocolate” sounds sensible, but it keeps the chocolate in the sentence. In studies of plans shaped this way, “then I won’t” plans made the old habit come to mind more, not less, and the effect was strongest when the habit was strong.

So give the moment something to do instead: “if I’m stressed, then I’ll make a cup of tea and step outside for five minutes.” The plan builder above will nudge you if a “then” turns into a “won’t”.

Expect it to take longer than starting

Breaking a habit also seems to be harder than building one. In a review of 23 studies on eating, if-then plans had a moderate effect on adding healthy food, such as eating more fruit, but a smaller effect on cutting down on unhealthy snacks. An old habit has had years of repetition in the same setting, and a new plan is competing with all of it.

That’s a reason to be patient with the plan, not to give it up, and to pair it with the things that make an old habit easier to leave behind, such as changing the setting where it usually happens. Habits tend to loosen when the setting changes, and a move, a new job or even a rearranged kitchen can be a good moment to start.

So when the alarm goes off on Monday and it’s raining a little, the decision was already made on Sunday evening: twenty minutes of exercise at home, and the email can wait.