Book Summary: Stumbling on Happiness by Daniel Gilbert

Book Cover for Stumbling on Happiness by Daniel Gilbert

In Stumbling on Happiness, Daniel Gilbert explains why we consistently err in predicting what will make us happy. It’s a funny and quirky foray into the field of happiness; more of a psychology book than self-help. While Gilbert does offer a clear suggestion for how to make better predictions, he does not seem to expect readers to take it.

Buy Stumbling on Happiness at: Amazon | Kobo (affiliate links)

Check out my summaries of other books on happiness and decision-making:

Key Takeaways

  • Happiness is hard to measure, because it’s a subjective state.
    • People may use different words to describe the same feeling.
    • Even experiences by the same person at different times are hard to compare as our memories are faulty.
    • The best we can do is take the honest, real-time report of the attentive individual and remember that it’s imperfect.
  • The feeling of control makes us happy. But not for what it gets us, because our predictions are consistently wrong.
  • Our predictions of the future are consistently wrong because:
    • We predict the future by simulating an event in our mind and reacting to it (“pre-feeling”).
    • Pre-feeling is very inaccurate — we anchor too much on the present, we focus too much on some things and neglect others, and we have an optimism bias.
    • Our brains also protect us from very bad events (but not mildly bad ones) by rationalising them; and we fail to account for this in our predictions.
  • We could make better predictions by asking others who are currently experiencing the future we are trying to predict how they feel.
  • However, we tend to disregard others’ advice and overestimate our own uniqueness.

Detailed Summary of Stumbling on Happiness

What is happiness?

“Happiness” has at least three meanings:

  • Emotional happiness. A feeling, an experience, a purely subjective state.
  • Moral happiness. For a long time, philosophers have conflated happiness with virtue. However, Gilbert argues that if living your life virtuously is a cause of happiness, it’s not happiness itself, and it just causes confusion to use the same term to describe both the cause and the consequence.
  • Judgmental happiness. When people say they are “happy about” something, or “happy that” an event occurred, they’re not actually saying they’re experiencing the feeling of happiness. Instead, they’re using the word to express their beliefs about the merits of something.

People frequently mix up these different types of happiness, which causes a big mess. In Stumbling on Happiness, Gilbert focuses on the first meaning — emotional happiness.

How to compare two different experiences?

Happiness is a subjective state

Philosophers like to say that subjective states are “irreducible”, in that nothing we can describe or compare it with can fully substitute for the experience itself.

For example, the way you experience yellow is a subjective, psychological state. It is what you experience when your eyes are struck by light with a wavelength of 580 nanometers. You can’t be sure that someone else has the same experience as you when struck by the same wavelength, even if you both use the same label (“yellow”) to describe it. Because shared labels can hide the fact that we may be having very different experiences, many people don’t find out they are colourblind until quite late in life.

Conjoined twins

Most people cannot imagine being happy as a conjoined twin. We think of all the pleasant experiences we singletons have, that they could never have, and imagine that their life must be quite unhappy. Conventional medical wisdom held that conjoined twins should be separated at birth, even if it risked killing one or both of them.

Yet Lori and Reba, an actual pair of conjoined twins, say they are happy. Not just “resigned to their fate” kind of happy — they’re joyful and optimistic, and couldn’t imagine being separated. And that desire to remain together seems to be universal among conjoined twins. They’ve experienced joys and pleasures of being together that most of us never have, and thus could never imagine.

Different people describe things differently

Even if two people use the same “objective” scale to rate their experiences, we can’t know for sure how the two subjective experiences compare.

There are two hypotheses in this area:

  • Language-squishing hypothesis. People have the same experiences but talk about them differently.
  • Experience-stretching hypothesis. People have different experiences, but describe them in the same way.

For example, say a kid listens to music using cheap $10 earbuds. He rates his happiness listening to that music as 9 out of 10. On his 16th birthday, he gets a set of expensive premium headphones. The kid becomes a true audiophile and is able to appreciate music in a way he never could before. He now rates his happiness listening to music as 10 out of 10. When asked how happy he was listening to music with crappy earbuds, he might, with hindsight, give it a 6.

The language-squishing hypothesis would say that, when the kid rated his happiness as 9 out of 10, he didn’t know what he was missing. He only gave such a high rating because he’d never experienced master quality audio, and didn’t know what “true” happiness was. There’s simply no way someone listening to music with crappy $10 earbuds could be that happy with it.

The experience-stretching hypothesis would say that trying the premium headphones changed the kid’s experiential background (and inadvertently ruined his ability to enjoy music with cheap earbuds, because now he knows what he’s missing). Once we have an experience, we cannot see the world as we did before. It’s not that the kid was wrong give a 9 out of 10 rating to listening to music with cheap earbuds — for him, the experience really was that great back then. But his preferences have changed, so the same audio quality no longer gives him the same subjective experience.

We can’t say which hypothesis is correct. The point is that all claims of happiness are claims from someone’s point of view. There isn’t a purely objective “view from nowhere”. [It’s clear that Gilbert prefers the experience-stretching hypothesis, though. Also note — the example above is loosely based on Gilbert’s examples, but I found some parts confusing so I changed it to make it more realistic and understandable.]

Even experiences by the same person are hard to compare because our memories are faulty

If we try to compare our happiness now to our happiness in the past, we’re at best comparing our current experience with a memory of a past experience. When we recount how we didn’t like how a wine tasted, we don’t replay our experience of how the wine actually tasted. Our brains don’t have the capacity to store our rich, multidimensional experiences in full. So, instead, we store a little summary of our experience in our memory. What we remember is our summary, not the experience itself.

Even if our brains could store a full experience, retrieving a memory would require precisely the amount of time that the event being remembered had originally taken. When we recall a experience, we don’t actually retrieve the experience itself — we use the little summary we have to quickly and effortlessly fabricate the bulk of the information. Each time we do this, we end up slightly altering the memory.

Remember which colour swatch you chose?

In one study, researchers showed volunteers a colour swatch for 5 seconds. One group then spent 30 seconds describing the colour (describers), while the other group was just made to wait 3- seconds (non-describers). All volunteers were then shown six colour swatches and asked to pick out the original swatch.

Of the non-describers, 73% were able to identify the swatch accurately. But of the describers, only 33% could do so. It appears the describers’ verbal descriptions of their experiences ‘overwrote’ their memories of the experiences themselves.

All of this means that when people have new experiences that lead them to claim that their language was squished (e.g. that he was not as happy listening to music through cheap earbuds as he said at the time) they can be mistaken. They’re only comparing their current experience to their memory, not to the past experience itself.

Happiness is hard to measure

We can be wrong about our own experiences

Research shows that physiological arousal can be interpreted in more than one way, and the interpretation we adopt depends on what we believe caused it. As soon as we encounter something, our brains instantly analyse its key features and decide whether we need to respond immediately. Our brains are evolved to decide whether an object is scary before we even work out what the object is. So it is possible to mistake fear for lust, apprehension for guilt, shame for anxiety, etc.

There’s a difference between awareness and experience. Awareness is kind of like an experience of our own experience. Most of the time, awareness and experience go together. Yet they actually involve different parts of the brain and some forms of brain damage can impact one without hurting the other.


Patients with a condition called “blindsight” have no awareness of seeing. They will say they are completely blind, and brain scans show diminished activity in the areas associated with awareness of visual experience. However, brain scans also show relatively normal activity in the areas associated with vision.

A study showed that when researchers flashed a light on a particular spot on the wall, the blindsight patients will say they didn’t see the flash. But if they’re forced ‘to make a guess about where the light might have appeared, the patients will “guess” correctly far more often than chance would suggest.

Awareness and experience can also become separated when it comes to our emotions. The degree to which people are aware of their moods and feelings can differ significantly. People with alexithymia (literally meaning “absence of words to describe emotional states”) are not able describe how they are feeling at all. They still seem to have feelings — their physiological responses when shown emotionally evocative pictures of amputations or car wreck look perfectly normal. Yet when they are asked to verbally rate the unpleasantness of those pictures, alexithymics struggle. [Unsurprisingly, alexithymia is highly prevalent among autistic people.]

Measuring happiness is tough, but possible

Happiness cannot be studied scientifically unless it can be measured. Though happiness is tough to measure, it’s not impossible.

We just need to accept that:

  1. Like chronometers, thermometers, and all other measurement tools, the tools we use to measure happiness will be imperfect.
  2. The honest, real-time report of the attentive individual is the best tool we have. We can cross-check these with bodily events (muscle movements, cerebral blood flow), but the only reason we take these events as indicators of happiness is because people tell us they’re happy.
  3. Measurement errors are only a dealbreaker if we don’t recognise them. In particular, large samples can help smooth out measurement errors. We can’t compare the reported subjective experiences of two people, but if we try to compare the reported experiences of two thousand people, the different calibrations begin to cancel out. [Yes, unless groups have systematic differences in their calibrations — e.g. when researchers try to make cross-cultural comparisons.]

The feeling of control makes us happy

The feeling of control over our lives makes us happy and increases confidence. People feel more confident in a dice toss if they throw the dice themselves. They’ll also wager more money on untossed dice than on dice that have already been tossed but whose outcome is not yet known.


  • There’s an asymmetry here. Gaining control positively impacts health and well-being, but losing control can be worse than never having had it.
  • The reason control makes us happy is not due to what control gets us (because we’re really bad at predicting what makes us happy). It’s the feeling of control itself that makes us happy, even if it’s just an illusion.

We predict the future by prefeeling

Our major life decisions are largely based on our beliefs about how we would feel if we took one course of action compared to another.

We predict how we’d feel in the future by conjuring up mental images of events, much in the same way we conjure up mental images of objects. Gilbert calls this prefeeling.

When we imagine objects, most people conjure up a vague picture of the object in our heads. This process activates the visual cortex, the part of our brain involved in seeing. Similarly, imagining a tune in your head activates the auditory cortex. (This is why it helps to close your eyes when you want to imagine an object, or block your ears when you want to recall the melody of a certain song.)

When we try to imagine we’d feel if some event occurred, we conjure up a mental image and react to that. For example, if you try to predict how you’d feel finding out your partner has been cheating on you, you’ll likely generate a mental image of the infidelity and emotionally react to it.

Prefeeling is usually a pretty good predictor of how we’d actually feel, and often better than logically thinking through the pros and cons of the possible future events. But, as explained below, prefeeling has limits.

Why are our predictions consistently wrong?

We’re not very good at knowing what makes us happy. Like perception errors caused by optical illusions, the mistakes we make when predicting what will make our future selves happy are lawful, regular and systematic.

Gilbert offers up many reasons why our predictions are consistently wrong:

  • Optimism bias;
  • Our minds fill in blanks without us noticing;
  • We overfocus on one thing and omit others;
  • For commitments in the far future, we focus on the why instead of the how;
  • We anchor based on the present;
  • We overestimate how much variety we want;
  • Our brains protect us from very bad events without us noticing.

Optimism bias

When people find it easy to imagine an event, they overestimate the likelihood that it will occur.

Most of us have much more practice imagining good events, so it comes more easily. This results in an optimism bias.

Our minds fill in blanks without us noticing

The problem isn’t necessarily that our brains fill in blanks, but that they do this so well that we don’t even notice.

For example, if you’re asked to imagine how happy you’d be eating spaghetti for dinner tomorrow, your brain likely added all sorts of details about the spaghetti. You weren’t told whether the spaghetti was from a can, restaurant, or home-cooked, nor did you know what sauce it would come with, but your brain likely filled in those gaps automatically.

We over-focus on one thing and omit others

When asked to imagine how they would feel after some event happened, people focus too much on that event and neglect all the other stuff in life that affects their happiness.

For example, Gilbert often asks people to imagine how they would feel two years after the sudden death of their child. They tend to focus on things related to the death, like hearing the news or attending the funeral. No one imagines all the other things that would inevitably happen in the two years following, such as attending another child’s school play or making love with their spouse.

Similarly, when people imagine being blind or disabled, they focus on just that. Yet a blind or disabled person’s life is about much more than their disability, and we overlook those other facets.

Describers vs non-describers

In one study, college students predicted how they would feel a few days after their school’s football team won or lost an upcoming game. One group (the describers) was asked to describe the events of a typical day before making their predictions. The other group (the non-describers) was not.

The non-describers drastically overestimated the impact that the win or the loss would have on them. When non-describers imagined the future, they only focused on one aspect of the future — the outcome of the football game — and neglected all the other things that would influence their happiness.

For commitments in the far future, we focus on the why instead of the how

We can imagine the near future with much more detail than the far future. When we make a commitment in the far future, we focus on the why (the causes and consequences) instead of the how (the execution).

For example, when we agree to babysit next month, we see it as an act of love. Whereas if we decide whether to babysit tonight, we focus more on the details of what that will entail. So commitments we make in the far future are more likely to be ones we end up regretting.

We anchor based on the present

When we try to predict how we’ll feel in the future, we generally imagine how we’d feel if those things happened now, and make some allowance for the fact that it will happen later. We use the present as an anchor for our prediction.

If you asked a child to count upward from zero and another child to count downward from a million, you could be pretty sure that when they finally got exhausted, gave up and went off in search of eggs to throw at your garage door, they would have reached very different numbers.
— Daniel Gilbert in Stumbling on Happiness

There are three problems with this:

  • Anchors have a large impact on our ending point. As a result, we generally expect the future will be much more like the present than it is (see e.g. all futurist books).
  • Anchors are stronger when we’re emotional or under pressure. When we’re under pressure or distracted, we end up very close to our starting points. This is because we can’t feel two things simultaneously. Our current senses and emotions will dominate because our brains (sensibly) prioritise reality. And, unlike mental images or sounds, which are clearly figments, feelings are messier to sort out. Depressed people for example find it hard to imagine feeling good about future events because they feel depressed now.
  • We fail to recognise that the comparisons we make in the future will be different. How much we value something depends on what we’re comparing it to. But we often fail to recognise that the comparisons we make in the future are likely to differ from the comparisons we are making now. For example, stores and advertisements often invite you to draw comparisons that will make you more likely to buy a particular product. Side-by-side comparisons will direct your attention to the differences between two products, even if those differences are not things you care about.

Do you care how many words are in a dictionary?

One study gave three groups of people opportunities to bid on dictionaries.

  • Perfect condition, fewer words. The first group bid on a dictionary with 10,000 words in perfect condition. On average, they bid $24.31.
  • Torn cover, more words. The second group had the opportunity to bid on a dictionary with 20,000 words, but a torn cover. On average, they bid $20.
  • Both dictionaries. A third group was allowed to compare the two dictionaries side by side. On average, they bid $19 for the smaller dictionary and $27 for the larger one.

We overestimate how much variety we want

Many things are wonderful the first time, but their wonderfulness declines with repetition. Psychologists call this habituation.

There are two ways to beat habituation:

  • increase the variety of your experiences; OR
  • increase the amount of time in between repetitions.
    Note the “OR” above — if you have one of these ways, you don’t need the other. In fact, when there’s a sufficient gap in between repetitions, variety can end up being costly.

Diversification Bias

Researchers in one study asked volunteers to come to the lab for a snack once per week for several weeks. There were several groups:

  • Choosers. These volunteers (choosers) had to choose all their snacks in advance. They usually opted for a decent amount of variety.
  • No-variety. The researchers fed these volunteers their favourite snack every time.
  • Variety. The researchers fed these volunteers their favourite snack most times and their second-favourite snack other times.
    The researchers found that volunteers in the no-variety group were more satisfied than the volunteers in the variety group. Although most of us think we want variety, when the occasions are sufficiently far apart, variety actually makes us less satisfied.

We are prone to overlook (or at least underestimate) the time gap in between experiences. [Gilbert claims this is because we think about time like we think about space. As such, when we’re choosing snacks in advance, we picture all of them laid out in front of us, simultaneously, which is what leads us to choose too much variety. I found this unconvincing. If people really did imagine snacks in this way, they’d choose as much variety as possible and minimise duplications. Yet people seem to choose only a moderate amount of variety. So, while I think it’s fair to say we tend to overestimate the amount of variety that will make us happy, I’m dubious that the reason is because we think of time in a spatial way.]

Our brains protect us from very bad events

People consistently overestimate how bad they’ll feel in the future, and for how long, if something bad occurs. This is because we fail to account for our ability to rationalise such events.

Explanations determine how we feel about things

While all animals can learn from associations (e.g. touching that thing will hurt), humans are unusual in that we can also form explanations that allow us to learn more.

However, most things are ambiguous and explanations can change the nature or intensity of an experience. Unexplained events have a stronger emotional impact because they seem rare and unusual, and we are likely to keep thinking about them. When we think we understand an event (even if that explanation is wrong), we believe we know how it might happen again and can therefore stop thinking about it.

For there is nothing either good or bad, but thinking makes it so.
— Shakespeare, Hamlet Prince of Denmark

Studies show that writing about an unpleasant event can lead to significant improvements in subjective well-being and physical health and that people who write an explanation experience the greatest benefits. Explanations can similarly lessen positive events — a delightful mystery can prolong our happiness, yet people prefer to opt for clarity.

We massage the facts without noticing

While we might see the world through rose-coloured glasses, those glasses are not opaque. We need some grip on reality to survive. Our brains and eyes therefore have an agreement:

  • The eyes will look for information that comforts the brain; and
  • The brain will (mostly) accept what the eyes see.
A healthy psychological immune system strikes a balance that allows us to feel good enough to cope with our situation but bad enough to do something about it
— Daniel Gilbert in Stumbling on Happiness

When the facts don’t fit our preferred views, we just raise the standard of proof for what is a “fact”, making it impossible for anything to be proved. (This may be why minds don’t really change when simply given more facts.)

We’re so good at this, we don’t realise we do it. In fact, cooking the facts only works if we don’t notice it. So this messes up our predictions.

Rejected for ice cream taster role

Gilbert and others conducted a study where people applied for cushy jobs as an ice-cream taster. Beforehand, they were asked to estimate how they would feel if they were not chosen for the job. Some participants their application would be assessed by a single individual, while others believed it would be assessed by a group.

The study found that participants felt worse if they were rejected by a group. Gilbert explains this is because it’s much less ambiguous and much harder for our brains to come up with a positive and credible story when you’re rejected by a group than by an individual. But people did not anticipate this — they just thought of the sting of the rejection itself, and not of how their brains might protect them from that sting.

But our psychological immune systems have limits

Our psychological immune systems only protect us negative events past a certain threshold. Studies show that the vast majority of people who survive major traumas do quite well, with a significant portion even claiming that the trauma made their lives better. Counterintuitively, this means that we often feel better about very bad events (e.g. becoming disabled) than mildly bad events (e.g. stubbing your toe).

Our psychological immune systems are also more likely to trigger when we face something we can’t change. People tend to give better ratings to kitchen appliances after they buy them, jobs after they accept them, and colleges after they get into them. But we don’t realise that our brains work this way so we try to keep our options open, even if that makes us less happy. [The Paradox of Choice dives deeper into this idea.]

Why do we keep making these errors?

These cognitive errors are hard to fix because we learn just about everything in two ways:

  • Direct, firsthand knowledge.
  • Indirect, secondhand knowledge.
    There are problems with learning from our errors with both of these methods.

We don’t remember our first-hand experiences correctly

The problem is that we don’t remember experiences correctly. Gilbert discusses three types of errors in remembering:

  • Unusual instances. We are more likely to remember unusual experiences and therefore overestimate their frequency. For example, when asked to predict how they’d feel if they missed their train that day, people expected it to be much more frustrating than it was. Because they’d call to mind their worst, most memorable, past experiences of missing their train.
  • Endings. We are more likely to remember how experiences ended. This is why women generally remember childbirth as less painful than it was.
  • Theories. We come up with theories to guess how we felt in the past based on what we remember about it.

Curiously, how we expect to feel can match up perfectly with how we remember we felt, even if neither of those matches how we actually felt:

US Presidential Election: Bush vs Gore

The 2000 US Presidential Election was an incredibly close one between George W Bush and Al Gore. It ultimately came down to who won Florida, and the margin was so thin that there had to be a recount.

Researchers surveyed voters on how happy they expected to be if Bush or Gore ended up winning, and again when the result was announced. Consistent with other studies discussed above, voters overestimated how happy or sad the election result would make them feel.

What was interesting in this case was that the voters were surveyed again a few months after the election. Both pro-Gore and pro-Bush voters remembered feeling as they had expected to feel, and not as they had actually felt.

This all makes it incredibly hard — if not impossible — for us to discover our errors and learn from our mistakes. As Gilbert explains:

The theories that lead us to predict that an event will make us happy (“If Bush wins, I’ll be elated”) also lead us to remember that it did (“When Bush won, I was elated”), thereby eliminating evidence of their own inaccuracy.
— Daniel Gilbert in Stumbling on Happiness

Learning from others is hard, too

Gilbert discusses two reasons why learning from others is challenging:

  • Beliefs that are likely to spread are not necessarily true and;
  • We often disregard others’ advice because we overestimate our uniqueness.

[I’m not sure it’s true that we really are bad at learning from others. Gilbert bases this on how often Americans move, change jobs, and remarry on average. Yet I don’t think these, especially the first two, necessarily imply a mistake — people do, after all, change over time.]

Beliefs that are likely to spread may not be true

Gilbert discusses memetics — the idea that some beliefs are transmitted more successfully than others because of their inherent properties, like how some genes are transmitted more successfully than others thanks to natural selection. For example, an accurate belief is more likely to be transmitted because accurate beliefs give us power.

But even a false belief that encourages a stable society is more likely to be transmitted, because stable societies make it easier for beliefs to be transmitted in general. False beliefs can therefore be propagated even without anyone trying to defraud the public.

Gilbert surmises that the belief that money leads to happiness is such a super-replicating false belief:

the production of wealth does not necessarily make individuals happy, but it does serve the needs of an economy, which serves the needs of a stable society, which serves as a network for the propagation of delusional beliefs about happiness and wealth
— Daniel Gilbert in Stumbling on Happiness

Another possible example is the belief that having children will make us happy — because societies that don’t hold this belief tend to die out. Both those who expect to have children and those who look back on parenthood view it with rose-tinted glasses. But those who actually have children feel very differently (especially women). [This is arguably rational though, if you’re optimising for long-term “remembered” happiness.]

We disregard others’ advice and overestimate our uniqueness

One way to correct most of the cognitive errors described above is by asking other people who are currently experiencing what we plan to do in the future how they feel. Gilbert calls this “surrogation”. For example, we can ask someone currently working in the job we want how they feel about it.

Studies have shown that volunteers are much more accurate in predicting their future feelings when they “surrogate” than when they had to “simulate” imagine how they’d feel themselves. [These studies were conducted by Gilbert and co-authors. They don’t appear to have been published.]

However, hardly anyone actually does this because we all seem to think we’re unique. (To be fair, we probably overestimate everyone’s uniqueness, because we tend to focus on our differences more than our similarities.) As a result, most of us see ourselves as less biased than average, so feel more comfortable simulating than surrogating.

Other Interesting Points

  • Chronically depressed people seem to be generally immune to the illusion of control. They tend to estimate more accurately the degree to which they can control events.
  • Subatomic particles have the ability to exist in two places at once.
  • Wilbur Wright had said to his brother that ‘man would not fly for 50 years’. He said this in 1901. The Wright Brothers’ first flight was in 1903.
  • Time is an abstraction, which makes it difficult to imagine. Sometimes we’ll try to make sense of it by thinking of something concrete instead, like space — we say the past is “behind” us and the future is “in front of” us. We draw timelines to try and make sense of when different events occurred.

My Thoughts

Stumbling on Happiness was enjoyable and easy-to-read. Gilbert’s writing style is very playful, which made the book quite fun, even for people who might usually balk at non-fiction. The book also contains various mini puzzles and optical illusions to keep you engaged throughout. However, sometimes the links back to Gilbert’s point seemed tenuous and it felt like he just wanted to share something cool with you.

The book also appears to be well-researched, with copious citations to back up its points (these are in footnotes, so they’re not distracting). I found Gilbert to be a generally credible writer, though I disagreed with him on a few minor points.

I read this shortly after The Paradox of Choice and there is a fair amount of overlap in the ideas raised. They are, after all, both books about happiness. Of the two, I’d say Stumbling on Happiness is the better written and more enjoyable read, though I personally found the ideas in The Paradox of Choice more interesting and useful.

Buy Stumbling on Happiness at: Amazon | Kobo <– These are affiliate links, which means I’ll earn a small commission if you make a purchase through these links. I’d be grateful if you considered supporting the site in this way! 🙂

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