Consistency — The Sturdiest Habit That Builds Trust

• Opening — The Trust Built by Small Promises
• Core Insight — Trust Comes From Predictability
• Going Deeper 1 — Matching Words and Actions
• Going Deeper 2 — The Compounding of Small Promises
• Going Deeper 3 — Identity-Based Habits
• Going Deeper 4 — The Cycle of Self-Trust
• Application 1 — Reducing Variability
• A Concrete Case — How I Built the Blog Habit
• The Art of Recovery — How to Come Back After Missing
• Application 2 — Consistency in Team and Work
• The Leader Consistency — A Contrast of Two Scenes
• Application 3 — Reputation Is a Line, Not a Point
• A Concrete Case 2 — Turning an Exercise Habit Into Identity
• Measurement — Making Consistency Visible
• Pitfalls and Balance — Beware of Rigid Consistency
• Consistency vs Stubbornness — A Deeper Look
• Another Pitfall — Confusing Consistency With Perfectionism
• How Trust Is Built — The Working Mechanism
• Another Balance — Consistency and Self-Compassion
• A Practical Framework — The Five Pillars of Consistency
• A 30-Day Starter Plan — Pick Just One
• Practice Checklist
• Going Deeper 5 — Consistency Across Contexts
• Frequently Asked Questions
• Closing — Sturdiness Beats Flash
• References

Opening — The Trust Built by Small Promises

I learned one thing running a blog. A steady stream of posts builds more trust than one dazzling piece. Readers trust someone who posts at a similar time with similar quality every week more than someone who occasionally writes one remarkable post. Because they are predictable.

This realization held just as true at work. The colleague I trusted most at LINE was not the smartest person but the most consistent one. When he said "I will review this by tomorrow," he reviewed it by tomorrow. It was a small promise, but as those small promises piled up, I came to hand him the big tasks too. By contrast, someone highly capable but different from one day to the next made me hesitate to entrust important work.

Consistency is not flashy. Pick out a single day and it looks ordinary. But viewed over a long span, few things build trust and reputation as powerfully as consistency. This essay covers why consistency is the foundation of trust, how to build it at the level of identity, and how to avoid the trap of consistency turning rigid.

Core Insight — Trust Comes From Predictability

What is trust? There are many definitions, but practically, trust leans heavily on predictability. To trust someone is to be able to predict, to some degree, how they will act going forward, and to believe that prediction will not work against me.

The role of consistency becomes clear here. The more consistent the behavior, the higher the predictability; the higher the predictability, the more trust accumulates. Conversely, when behavior is erratic, the other side feels uneasy no matter how capable you are, because they do not know how you will turn out next time.

This leads to reputation. Reputation is, in the end, other people compressed prediction that "this is the kind of person they are." Reputation forms from a pattern of repeated behavior more than from a single intense event. Consistency is the force that makes that pattern clear.

Going Deeper 1 — Matching Words and Actions

The most basic form of consistency is the match between words and actions. Doing what you said, and saying what you did. It looks simple, but people who steadily pull off this simple thing are surprisingly rare.

There are usually two reasons words and actions diverge.

First, over-promising. To look good in the moment, or because saying no is hard, you promise something hard to keep. And you fail to keep it. When small breaks repeat, the reputation forms that "you should only half-believe what that person says."

Second, the absence of recording and tracking. You forget what you promised. There is no malice, but the result is the same.

To prevent this I use two principles. One is "under-promise, over-deliver." When I am not certain, I lower the strength of the promise. Instead of "I will finish today," I say "I will definitely get it to you by tomorrow." The other is "record what you said immediately." A promise that leaves my mouth gets written down before I forget.

Going Deeper 2 — The Compounding of Small Promises

A common misunderstanding about consistency is that it comes from big resolutions. The truth is the opposite. Consistency grows from keeping very small promises.

There are two kinds of promises here. Promises made to others, and promises made to yourself.

Keeping small promises to others builds trust. Keeping small promises to yourself builds self-trust. And this self-trust becomes the fuel for greater consistency. Once the self-perception "I am someone who does what I say" forms, keeping the next promise gets easier.

The reverse direction works too. Keep breaking promises to yourself and the self-perception "I am someone who cannot keep promises anyway" forms. Then you start treating the next promise lightly to begin with. It is a vicious cycle where breaking small promises erodes self-trust.

The thing that best shows the power of small promises is compounding. On any single day it is negligible, but stacked in the same direction every day, the gap widens exponentially. Assume you improve by 1 percent each day, and a year later you are roughly 37 times better. Conversely, decline by 1 percent each day and a year later you converge toward zero. Below is a simplified picture of how trust capital diverges when you keep small promises daily versus when you break them.

Compounding of trust capital (starting value 1.00)

Keep +1% daily               Break -1% daily
Day 1    | 1.01              Day 1    | 0.99
Day 30   | 1.35              Day 30   | 0.74
Day 90   | 2.45              Day 90   | 0.40
Day 180  | 6.02              Day 180  | 0.16
Day 365  | 37.78             Day 365  | 0.03

The same single day, opposite directions.
A month is no big gap, but a year makes you a completely different person.

The core of this picture is simple. Any one day promise is small, but the direction in which those small promises accumulate is what ultimately defines who you are. So consistency is not a matter of grand decisions but a matter of direction.

Going Deeper 3 — Identity-Based Habits

In "Atomic Habits," James Clear divides behavior change into three layers: outcome-based (what you will get), process-based (what you will do), and identity-based (what kind of person you will be). He argues that the most durable change happens at the identity layer.

This connects deeply with consistency. "I should write every week" is a resolution about outcome or process. It wavers when willpower weakens. By contrast, "I am someone who writes every week" is a statement of identity. When identity and behavior match, consistency is no longer something squeezed out by willpower but an expression of yourself.

Clear suggests treating behavior as a "vote" for your identity. Each small action is a vote cast for "this is the kind of person I am." One vote does not change an identity, but as votes accumulate, the majority is decided. Consistency is the work of steadily casting votes in the same direction.

Going Deeper 4 — The Cycle of Self-Trust

As important as the trust you receive from others is the trust you have in yourself. I call this the "self-trust loop." Keep a promise to yourself and your self-trust rises; as self-trust rises, the next promise gets easier to keep. It is a virtuous cycle.

The loop turns through four stages. You make a small promise. You keep it. Evidence accumulates that "I am someone who keeps promises." That evidence creates the confidence to keep the next promise. And then it returns to the first stage. Each time around, the loop grows a little sturdier.

The problem is that this loop also turns the other way. Break a promise and evidence accumulates that "I am someone who cannot keep promises," that evidence makes the next promise feel light, and you break it more often. The same structure works both upward and downward, so the direction you turn it is decisive.

The practical lesson of this table is that if you want to change the direction of the loop, touch the easiest point. The direction turns not through some grand resolution but through keeping one small, keepable promise. Self-trust accumulates as evidence, not as declaration.

Application 1 — Reducing Variability

One concrete way to practice consistency is "reducing variability." The enemy of consistency is not only laziness. Erraticness — variability — is also an enemy.

Take exercise. Doing two hours one day and resting for several days is worse over the long run than doing twenty minutes every day. Writing is the same. Writing in a binge on days inspiration comes and not a line on days it does not is worse than writing a steady small amount every day, which in the end gets you to write more and more steadily.

Practical ways to reduce variability.

1. Set a minimum bar. Instead of "write," set a very low floor like "write at least one paragraph." Keep this floor even when your condition is poor.
2. Same time, same place. Fixing a behavior to a specific time and place reduces the drain on willpower.
3. Do not break the streak. Put in a rule that missing one day is fine but you never miss two days in a row. It stops a single exception from becoming a pattern.

A Concrete Case — How I Built the Blog Habit

Abstract principles only become tangible when you handle them through a case. Let me walk through, step by step, how I came to write this blog steadily. It did not go well from the start. In the early days, when enthusiasm ran ahead, I resolved to "write a deep, long piece every week," and collapsed within two weeks. The resolution was too big and the bar was too high.

When I started again, I borrowed BJ Fogg idea of "Tiny Habits." Fogg says to set the starting point of change "absurdly small." So I changed my resolution like this.

Step one, I set the minimum unit. Not "write a long piece" but "open my notes in the morning and write three sentences." Three sentences was a floor I could keep even when my condition was poor and even when I was busy.

Step two, I attached the behavior to an existing habit. This is what Fogg calls an "anchor." I had a habit of brewing coffee in the morning, so I connected it as "after I brew coffee, I open my notes." No new willpower to squeeze out; I rode on a flow that already existed.

Step three, I restated it as identity. Not "I have to write" but "I am someone who writes every day," I told myself. Every time I wrote three sentences, I thought of it as casting one vote for that identity.

Step four, I tracked it. I marked the days I wrote on a calendar. Just watching the marks continue gave me the desire not to break the chain.

After a few weeks like this, three sentences often became a paragraph, and a paragraph often became a full piece. What mattered was not the volume but that the self-perception of being "someone who writes" had grown sturdy.

The Art of Recovery — How to Come Back After Missing

The real test comes not when things go well but when you have missed. There have been many times when a business trip, late-night work, or a bad cold kept me from opening my notes for several days. Each time, what nearly broke me was not the fact of missing itself but the thought "the chain is already broken, so this month is a write-off."

The rule I use for recovery is this.

Recovery rule (miss recovery)

1. No self-blame. A miss is just data, not a verdict on your character.
2. Return to the floor. The next day, do not try to do something grand;
   come back only at the smallest unit (three sentences).
3. The two-day rule. Missing one day is allowed, two in a row is not.
4. Record the cause in one line. Write one line on why you missed, to see the pattern.
5. The next vote. Focus only on "the one vote I cast again today."

The key is to see a missed day not as a "zero" but as "one point that nudged the average slightly down." Consistency is a matter not of 100 percent but of a high rate, so a single gap is fully recoverable. What is actually dangerous is not the gap itself but letting go of the whole average line, using the gap as an excuse.

Application 2 — Consistency in Team and Work

At work, consistency goes beyond personal trust to team efficiency. When colleagues can predict my behavior, the cost of unnecessary checking and coordination drops.

Scenes at work where consistency becomes trust.

• Schedule promises. Keep deadlines you state, or tell people early if you might miss one. The consistency of giving early notice, even when late, protects trust.
• Quality bar. Instead of doing sloppy or meticulous work depending on the day mood, hold a steady quality bar.
• Communication style. Share transparently with the same attitude whether the news is good or bad.
• Feedback attitude. Keep evaluation standards from shifting by person or by mood.

In leadership, consistency matters especially. If you get angry at the same mistake one day and let it slide another, team members watch the leader mood rather than the rules. Under a predictable leader, people work with ease.

Harvard Business Review "The Neuroscience of Trust" reports that high-trust organizations have markedly higher productivity and engagement than low-trust ones. A large share of that trust comes from leaders matching their words to their actions and applying standards predictably. Consistency, then, is not merely a personal virtue but a variable in organizational performance.

The Leader Consistency — A Contrast of Two Scenes

To show how a leader consistency works differently on a team, let me sketch the same situation as two versions of a conversation. A team member has gone one day past a deadline.

[The inconsistent leader]

(Last week) Member: The schedule is tight, I think I will be a day late.
Leader: It is fine, that happens. Do not worry about it.

(This week, a different member in the same situation)
Member: I am sorry, I think I will be a day late.
Leader: What, late on this too? How is anything supposed to get done?

-> The members conclusion: "There are no standards. Only the leader mood."
-> Behavior change: they read the leader expression before the schedule.

[The consistent leader]

(Last week) Member: The schedule is tight, I think I will be a day late.
Leader: Thanks for telling me. Letting me know early when you might be late
        is the most important thing. Let us set a new schedule together.

(This week, a different member in the same situation)
Member: I am sorry, I think I will be a day late.
Leader: Thanks for the early heads-up. Let us look at what is blocked
        and adjust the schedule if we need to.

-> The members conclusion: "The standard is clear. Giving early notice is safe."
-> Behavior change: they share problems early instead of hiding them.

The difference between the two leaders is not the degree of leniency. The difference is predictability. The consistent leader applies the same principle (respect early notice) the same way every time. So the member can learn how to act safely. Under the inconsistent leader, by contrast, no one can tell what the right action is, so everyone turns defensive.

I experienced both types of leader at LINE. Looking back, I worked far more at ease under a leader who was somewhat strict but unwavering than under one who was warm but mercurial. When the standard is clear, all you have to do is meet it.

Application 3 — Reputation Is a Line, Not a Point

It is easy to think of reputation as a single photograph, but reputation is not a photo; it is a video. Not one frame, but a flow across time.

This perspective implies two things. One is that reputation accumulates slowly. You cannot build a good reputation overnight. The other is that, precisely for this reason, reputation can also recover. A single mistake does not decide a reputation forever. Show consistent behavior long enough after a mistake and the flow turns again. What matters is not one point but the line the points draw.

A Concrete Case 2 — Turning an Exercise Habit Into Identity

If the blog case was about using the head, I tested whether the same principle works in something physical, using exercise. To state the result up front, it worked exactly the same way. The key was the same: "small, by identity, with tracking."

The first attempt was, as always, grand. "Gym four times a week, an hour each time." This plan unfailingly collapsed once the first week passed. It demanded too much willpower all at once. So I redesigned it.

Exercise habit redesign

Old plan: gym 4x a week, 1 hour    -> collapsed in 2 weeks
Redesign: 10 squats every day      -> kept up for 6 months and counting

Anchor:    right after brushing teeth (already a daily action)
Floor:     even on the worst day, do 10 squats
Identity:  "I am someone who moves their body every day"
Tracking:  a circle on the calendar, do not break the streak
Expansion: on days the body loosens up, naturally do more (no forcing)

The most important change was the floor. "Ten squats" is a size for which it is hard to find an excuse to refuse. It is so small that it would be embarrassing to say "not today." Yet the real value of this tiny action was not the amount of exercise but that it let me cast one vote every day that "I did it again today." Once started, the days I stopped at ten were actually rare.

Once a business trip kept me from exercising for three days. In the old days I would have stopped right there, saying "the chain is already broken." But following the recovery rule, on the day I came back I did not try to make up for it grandly; I just returned with ten squats. That small return reconnected the flow. Six months later, I had become not "someone who resolves to exercise" but "someone who just moves every day."

Measurement — Making Consistency Visible

Consistency is abstract, so it is hard to manage. That is why making it visible matters. What is not visible does not get managed. The measurement method I use is simple.

First, the streak. The simple visualization of filling one box per day stirs the desire not to break that streak. But clinging only to the streak can make you crumble when it breaks once, so I use the streak only as a supporting indicator.

Second, the rate. I look at how many days out of a month I kept it. Twenty-five out of thirty is about 83 percent. Since the rate does not swing much even with a single miss, you fall less into the perfectionism trap. It is an indicator that lets you see consistency as a "high rate" rather than "all or nothing."

Third, the recovery speed. How many days it took to come back after missing. This may be the most important indicator. The real strength of consistency lies not in never missing but in coming back quickly after a miss.

Pitfalls and Balance — Beware of Rigid Consistency

Having praised consistency, it has a clear trap. It is when consistency degrades into rigidity.

Ralph Waldo Emerson said "a foolish consistency is the hobgoblin of little minds." When the situation has changed and new information has arrived, yet you stay bound to past words and decisions and cannot change, that is not consistency but stubbornness.

The criterion that separates healthy consistency from rigid consistency is "what you are consistent about."

• Be consistent about values and principles. It is good to hold fundamental values like honesty, keeping promises, and respecting people consistently.
• Be flexible about methods and opinions. Specific tactics, tools, and momentary opinions are better changed when better grounds appear; this actually raises trust.

In other words, changing your mind is not in itself a violation of consistency. Changing your mind for good reasons is growth. The problem is wavering without reason, or conversely not changing even when a reason has arrived.

Consistency vs Stubbornness — A Deeper Look

On the surface, consistency and stubbornness look alike. Both rarely change their stance and seem unwavering. So a stubborn person often dresses themselves up as "someone with conviction." But the two are fundamentally different. The question that separates them is just one. "Are you willing to change if better grounds appear?"

Consistency is fidelity to values. It does not waver on principles like honesty, keeping promises, and respecting people. But it stays open about the concrete methods that realize those principles. If a better path appears, it changes gladly. That is, consistency is steadiness about "what you are heading toward," not stubbornness about "how you get there."

Stubbornness is the opposite. It is faithful to one own stance itself rather than to values. Defending what you said, the decisions you made, and your own face becomes the goal. So even when new information arrives, you hold your stance "because you do not want to admit you were wrong." This is not fidelity but ego defense.

You can tell the two apart by three signals.

1. Reaction to grounds. A consistent person, hearing counter-evidence, says "interesting, let me reconsider." A stubborn person belittles the evidence with "that is an exception."
2. Attitude after changing. A consistent person, after changing their mind, says openly "I changed because a better reason came up." A stubborn person, even when they change, hides the fact or pretends they thought so all along.
3. What they are trying to protect. A consistent person tries to protect the principle. A stubborn person tries to protect the fact that they were right.

When Emerson said "a foolish consistency is the hobgoblin of little minds," what he criticized was not consistency itself but precisely this stubbornness. Throwing away today better judgment just to avoid contradicting yesterday self. That is not steadiness but being trapped in yesterday. Healthy consistency belongs, rather, to "someone willing to update their yesterday self."

I, too, have overturned the claim of an old post while writing this blog. At first I hesitated, thinking "what if it contradicts what I said before." But when I honestly wrote "in an earlier post I saw it this way, but here is why my thinking has since changed," trust was not chipped away; it was added to. What readers trust is not "someone who never changes" but "someone who explains honestly when they change."

Another Pitfall — Confusing Consistency With Perfectionism

It is common to fall into perfectionism while pursuing consistency. Gripped by the rule "I must do this every day," you miss one day and, declaring "it is all ruined," abandon everything. This misunderstands consistency as an all-or-nothing matter.

Consistency is not 100 percent perfection but a high rate of steadiness. One missed day does not collapse consistency. What truly collapses consistency is the attitude of letting go forever after one miss, saying "it is already broken." That is why a recovery rule like the earlier "never miss two days in a row" builds stronger consistency than perfectionism.

How Trust Is Built — The Working Mechanism

Let me break down a little more the process by which consistency builds trust. Trust does not appear all at once; it accumulates through repeated small verifications. The other person unconsciously compares, each time, what I said against what I actually did. Every time words and actions line up, the trust balance grows a little; every time they diverge, it shrinks.

There is an asymmetry here. Trust fills drop by drop, but it drains sharply with one big betrayal. So it is important to keep small promises steadily and build the balance thick. With a thick balance, an occasional mistake does not collapse the relationship. With a thin balance, conversely, a single small divergence shakes it.

This principle also explains why "under-promise, over-deliver" is so powerful. Set the promise low and the actual result easily exceeds it, and each time a small plus accrues to the trust balance. Set the promise high and, even doing well, you only break even, and falling a little short means a minus. Even with the same result, the direction of trust splits depending on where you set the expectation.

Same result, different trust

A: "I will finish today" -> done tomorrow   =  fell short (minus)
B: "I will get it by tomorrow" -> done tomorrow =  met (plus)

The deliverable is identical. The only difference is the height of the promise.

Another Balance — Consistency and Self-Compassion

There is one last balance I want to stress. In pursuing consistency, it easily degrades into a whip you drive yourself with. You blame yourself on every missed day and come to hate the self that fell short of the bar. But self-blame does not help consistency. It collapses it.

The reason self-blame collapses consistency is simple. It reinforces the negative self-perception that "I am someone who cannot keep promises." Recall the self-trust loop from earlier: self-blame is an act that pushes the loop in the vicious direction. The more you hate yourself on a missed day, the less confidence you have to keep the next promise.

So on a missed day you need self-compassion instead of self-blame. The attitude of "missed today; let me record it as data and come back tomorrow at a small unit." This is not a call to go easy on yourself; it is, rather, a strategy for staying consistent longer. Over a long distance, the person who soothes themselves and keeps coming back goes farther than the person who hates themselves.

In the end, real consistency is not flawless perfection but the persistence of repeatedly standing up from where you fell. The essence of steadiness lies not in never stopping but in starting again in the same direction each time you stop.

A Practical Framework — The Five Pillars of Consistency

1. Promise less. Promise only as much as you can keep, narrowing the gap between promise and result.
2. Record immediately. Write down promises made aloud and promises to yourself before you forget.
3. Set a minimum bar. Keep a low floor you can hold even when your condition is poor.
4. Speak in identity. Define behavior as "I am someone who does" rather than "I will do."
5. Firm on values, flexible on methods. Hold core values, but change methods in the face of better grounds.

A 30-Day Starter Plan — Pick Just One

Knowing the principle and starting are different. So let me lay out a 30-day plan for the smallest first step. The key is to pick exactly one habit, not several.

30-day consistency starter plan

Week 1 (design)
  - Pick just one habit (e.g., three sentences of writing, 10 squats)
  - Decide an anchor to attach it to an existing habit
  - Write an identity sentence: "I am someone who does OO"
  - Set a floor you can keep even on the worst day

Weeks 2 to 3 (repeat)
  - Each day fill only the floor. Do more if you want to
  - Record one box per day on a calendar
  - On a missed day, write only one line on the cause, no self-blame
  - Never miss two days in a row

Week 4 (review)
  - Look at the achievement rate and recovery speed
  - Adjust whether the floor was too high or too low
  - Check whether the identity sentence actually feels true

The goal of this plan is not to produce some great result within 30 days. It is to create one small piece of evidence that "I am someone who does what I say." That single piece of evidence becomes the foundation for keeping the next habit and the next promise. Consistency does not begin with a colossal resolution; it begins with a small 30-day experiment.

Practice Checklist

• Was the promise I made today one I can keep?
• Did I record what I promised so I do not forget?
• Did I keep a small promise to myself?
• Did I keep the minimum bar even when my condition was poor?
• Am I defining behavior at the level of identity?
• When new information came, did I hold core values but flexibly change methods?
• After one miss, did I return rather than abandon everything?

Going Deeper 5 — Consistency Across Contexts

The hardest consistency is not the day-to-day repetition but remaining the same person even as people and situations change. In front of those above you and those below you, when the camera is on and when it is off, when it benefits you and when it costs you. The person who acts on the same values across all these contexts is whom we call "steadfast."

The reason this is hard is that people instinctively adjust their behavior to the situation. Bending before the strong and being careless with the weak, keeping principles only when there are watching eyes, is a temptation everyone has. Yet people detect this difference with surprising accuracy. And the person who changes with context is, in the end, deeply trusted in no context at all.

I use a simple question to test this. "Would I do this exact thing if the person I most respect were watching?" If the behavior when no one is watching matches the behavior when someone is, that is real consistency. Reputation is made when others watch, but character is made when no one watches. And interestingly, the consistency of when no one watches makes, over the long run, the best reputation.

This contextual consistency seems unrelated to the small daily habits, but it actually grows from the same root. The person who has made the identity "I am someone who keeps promises" sturdy by keeping small promises acts on that identity even in moments no one watches. Once identity is sturdy enough, consistency is no longer a calculated choice based on the situation but simply who you are.

Frequently Asked Questions

Question: Are consistency and change not contradictory? You have to change to grow. Answer: They are not contradictory. The key is what you are consistent about. Being consistent about values and principles while flexibly changing the methods that realize them in the face of better grounds is healthy growth.

Question: Keeping consistency gets boring and my motivation drops. Answer: That is natural. Shifting focus from outcome or process to identity helps here. Instead of "I have to do it again today," thinking "this is a vote showing what kind of person I am" revives the meaning.

Question: What do I do when I become unable to keep a promise? Answer: Telling people as early and honestly as possible is best. Notifying late or hiding it damages trust more. More than failing to keep a promise, the consistency of how you handle it shapes reputation.

Closing — Sturdiness Beats Flash

If I compress what I learned from blogging and work into one sentence, it is this. Trust comes not from one act of flash but from long sturdiness.

Consistency does not shine. Pick out a day and it is ordinary, sometimes boring. But when those ordinary days pile up in the same direction, they become, before you know it, a trust and reputation no one can easily imitate. At the same time, so that consistency does not harden into rigidity, you must not forget the balance of being firm on values and flexible on methods.

I encourage you to recall one small promise you made to yourself today. Keeping it is a vote cast for the greater trust of tomorrow.

References

• James Clear, "Atomic Habits: An Easy and Proven Way to Build Good Habits and Break Bad Ones," Avery — https://jamesclear.com/atomic-habits
• James Clear, "Identity-Based Habits" — https://jamesclear.com/identity-based-habits
• Ralph Waldo Emerson, "Self-Reliance" (1841) — https://www.gutenberg.org/files/16643/16643-h/16643-h.htm
• Roy Baumeister, John Tierney, "Willpower: Rediscovering the Greatest Human Strength," Penguin Books.
• Harvard Business Review, "The Neuroscience of Trust" — https://hbr.org/2017/01/the-neuroscience-of-trust
• BJ Fogg, "Tiny Habits: The Small Changes That Change Everything," Houghton Mifflin Harcourt.