The evidence

Why keeping your word to yourself changes who you are.

Seven findings from published research, each with the citation and each with the part it does not prove. Read the honesty note at the bottom before you quote any of this at anyone.

Finding one

Identity moves behaviour more than intention does.

In a set of US voting experiments, people asked questions framed as a noun — how important is it to be a voter — turned out at meaningfully higher rates than people asked the same questions framed as a verb, about the act of voting. The effect was found across separate elections. A related set of studies found that asking people not to be "a cheater" reduced cheating more than asking them not to "cheat".

What we do with it: promises are written as things a person does, and the language throughout the product is about who you are becoming rather than what you are hitting. Nobody here has a target weight.

Bryan, Walton, Rogers & Dweck (2011), PNAS 108(31), 12653–12656. Bryan, Adams & Monin (2013), Journal of Experimental Psychology: General 142(4), 1001–1005.

The limit: these are single-action studies about voting and cheating, not about maintaining a habit for ninety days. The mechanism is well supported; the size of the effect over months is not established.

Finding two

Monitoring your progress reliably improves it, and recording it works better still.

A meta-analysis pooling 138 studies and 19,951 participants found that prompting people to monitor their goal progress produced a reliable improvement in goal attainment. The effect was larger when progress was physically recorded, and larger again when it was reported to somebody else.

What we do with it: daily sealing is the recording, and it goes to a named person rather than into a private void. Those are the two conditions the analysis found strengthened the effect.

Harkin et al. (2016), Psychological Bulletin 142(2), 198–229.

The limit: average effects across a very wide range of goals. Monitoring helps; it is not a guarantee for any one person.

Finding three

Commitment devices work, and they keep working after you stop paying attention.

Bank clients in the Philippines who were offered a savings account they could not withdraw from until a goal was met increased their savings balances by roughly 81% after twelve months relative to a control group. In a separate trial, smokers offered a deposit contract — put money aside, take a nicotine test in six months, forfeit it to charity if you fail — were about three percentage points more likely to pass, and the effect was still there in a surprise test at twelve months.

What we do with it: the signature, the locked seal, and the fact that a named person has your promises are all soft commitment devices. We deliberately do not take your money if you fail, because punishment changes who stays rather than who succeeds.

Ashraf, Karlan & Yin (2006), Quarterly Journal of Economics 121(2), 635–672. Giné, Karlan & Zinman (2010), American Economic Journal: Applied Economics 2(4), 213–235.

The limit: both involve money at risk, which we do not use. And in the savings study the effect had faded to a statistically insignificant level by two and a half years, which is a real and important caveat about how long any of this lasts on its own.

Finding four

Coaching produces measurable improvements in goal attainment.

A meta-analysis of 18 studies found workplace coaching improved goal attainment with a large effect size, along with smaller improvements in performance, wellbeing and coping. A second meta-analysis across 17 studies and 2,267 participants found a positive overall effect, with the strongest effects on results rather than on attitudes.

What we do with it: a Keeper is the smallest useful version of this — not a full coaching relationship, but a trained human with your goals in front of them and a duty to respond.

Theeboom, Beersma & van Vianen (2014), The Journal of Positive Psychology 9(1), 1–18. Jones, Woods & Guillaume (2016), Journal of Occupational and Organizational Psychology 89(2), 249–277.

The limit: these are studies of professional coaching in organisations, mostly with more contact time than a weekly message. They support the principle, not our specific format.

Finding five

Roughly 66 days to automatic, and one missed day does not undo it.

In a study following people adopting a new daily behaviour, the median time to reach automaticity was 66 days, with an enormous range from 18 to 254 days depending on the person and the behaviour. Missing a single day did not measurably harm the process. Sustained inconsistency did.

What we do with it: rule two, in its entirety. This is why a miss is not punished and why the streak you can lose is the honesty one, not the perfection one.

Lally, van Jaarsveld, Potts & Wardle (2010), European Journal of Social Psychology 40(6), 998–1009.

The limit: a small study, 96 participants, self-selected, and the "21 days" and "66 days" numbers are both wildly over-quoted. Treat 66 as a rough middle of a very wide range, not a deadline.

Finding six

Beating yourself up after a lapse makes the next lapse more likely.

Students who forgave themselves for procrastinating before a first exam went on to procrastinate less before the next one. The mechanism is straightforward: self-criticism after a slip adds a layer of bad feeling to the task itself, which you then avoid harder. Related work on the "what the hell" effect describes the same collapse — one broken rule, so the day is written off entirely.

What we do with it: owned days are neutral, not red. There is no shame colour anywhere in the product. A miss is grey, it costs nothing, and your Keeper's response to three of them is to make the promise smaller.

Wohl, Pychyl & Bennett (2010), Personality and Individual Differences 48(7), 803–808. See also Marlatt & Gordon's relapse-prevention work on the abstinence violation effect.

The limit: the forgiveness study is correlational and specific to procrastination in students.

Finding seven

You work out who you are by watching what you do.

Self-perception theory holds that when internal signals are weak or ambiguous, people infer their own attitudes from their own behaviour, much as an outside observer would. You do not decide you are disciplined and then act on it. You watch yourself keep your word thirty times and conclude something about yourself from the evidence.

What we do with it: this is the argument for the Receipt existing at all. The point of a permanent, unfakeable record is that it is evidence you can be shown, about yourself, by something other than your own memory — which is a famously unreliable witness on this subject.

Bem (1972), self-perception theory, in Advances in Experimental Social Psychology, vol. 6.

The limit: a foundational theory rather than a single trial, and like most of mid-century social psychology, parts of the surrounding literature have not replicated well. We rely on the general principle, not on any specific figure.

The one everybody quotes

About that "76% versus 43%" accountability statistic.

You will have seen it: people who wrote their goals down and sent weekly progress reports to a friend achieved far more of them than people who only thought about their goals. It comes from a study by Gail Matthews at Dominican University of California, and the direction of the finding is consistent with the meta-analytic evidence in finding two.

We are not putting it in our marketing, because as far as we can establish it was presented at a conference rather than published in a peer-reviewed journal, and it gets quoted with a confidence the original design does not support. It is the single most-cited number in this entire industry and almost nobody who cites it has checked where it came from.

We are telling you this because if we will flag a statistic that helps our argument, you can reasonably trust the ones we did keep.

The honesty note. Every study above validates a principle Promise Keepr is built on. None of them is a study of Promise Keepr. We are new, we have no outcome data of our own yet, and when we do have it we will publish it including the parts that make us look bad. Individual results vary enormously. Promise Keepr is coaching and accountability, not medical or mental health treatment, and nothing here is a clinical claim.

If you think we have got a citation wrong, or you know of evidence that cuts against something on this page, email hello@promisekeepr.com and we will correct it publicly.

Enough theory.

The research says a witness helps and an unfakeable record helps. There is only one way to find out whether it helps you.

First month refunded in full if you sealed your days and it did not work for you.

Make your first promise