Stumbling on Happiness Book Summary

The human brain is unique in the animal kingdom in its ability to mentally travel through time - to imagine the future in great detail before it happens. This allows humans to preview different futures and make decisions in the present to steer themselves toward the best possible tomorrow. Imagination is one of the most powerful gifts evolution has given to humans.

Section: 1, Chapter: 1

While people universally seek happiness, the word "happiness" itself is very hard to define precisely. Happiness refers to a subjective feeling, a personal experience. We can't point to happiness as an objective thing in the external world. And your experience of happiness is impossible for anyone else to access directly. When we talk about happiness, we're referring to an internal state that we know when we feel it, but struggle to put into words.

Consider the real-life case of conjoined twins Lori and Reba Schappell. Most people assume conjoined twins must be very unhappy being physically attached to each other for life. But Lori and Reba report being quite happy and wouldn't want to be separated. Is their experience of happiness the same as what non-conjoined people feel? There's no way to directly compare subjective experiences between individuals. We can't get "inside" their minds to feel what their version of happiness is like compared to ours.

Section: 2, Chapter: 2

Both when remembering the past and imagining the future, the human brain tends to "fill in" missing details that weren't originally stored, in order to construct a coherent scene or narrative.

• In memory, we don't store every detail of a past event. When we later retrieve that memory, the brain fills in plausible details to flesh it out, but these details may be inaccurate.
• When imagining a future event, the brain constructs a scene with many assumed details that may not match the actual details that will exist in that future moment.

In both cases, we aren't aware in the moment that our brain is "making up" details that feel real to us. We tend to trust that the details in our remembered and imagined scenes are accurate.

Section: 2, Chapter: 2

The human brain acts like a clever "editor" of our life experiences, not a perfect transcriptionist. Both in the present moment and when recalling memories, the brain unconsciously tweaks and fills in details to construct a cohesive narrative.

For example, in the present, the brain filters out details to focus on what it deems important. In memory, it reconstructs past events with plausible details to flesh out a clear story. The key is that this editing happens unconsciously - we aren't aware of it and tend to fully believe the edited version our brains present to us.

Section: 2, Chapter: 3

When we imagine future events, our brains are prone to making certain mistakes that we aren't consciously aware of in the moment:

We tend to fill in details of imagined events based on our current circumstances, rather than adjusting for how our circumstances may change in the future.

We tend to imagine the most salient details of an event (e.g. the moment of winning an award) but gloss over less exciting details (e.g. the boring acceptance speech).

We tend to imagine events in isolation and neglect to consider how they'll fit into the context of other events in our lives.

Because of these flaws, the way we imagine future events is often not accurate to how we'll actually experience those events if they come to pass. But we tend to trust our imaginations and make decisions accordingly.

Section: 3, Chapter: 4

When imagining future events, we tend to fill the scene with details of what will be present. But we fail to consider what will be absent:

• We imagine how great it will feel to have a new car stereo but forget that we won't have the $500 we spend on it.
• We imagine the fun of playing with a new puppy but neglect the absence of free time we'll experience.
• We imagine how impressive our new job title will sound but not the absence of our previous coworker friendships.

Because imagined events feel real and detailed to us, we don't notice the missing pieces. In reality, what's absent from the scene (money, time, friends) will influence our real experience as much as what's present.

Section: 3, Chapter: 5

When imagining the future, the human brain relies heavily on the details of the present moment to fill in the details. This leads to mispredictions when the future is actually different from the present:

• When we're hungry, we overshop because we assume we'll be as hungry in the future.
• When we're in love, we assume we'll feel as passionately in the future.
• When current events are going well, we imagine that trajectory continuing into the future.

In reality, our circumstances, values, and tastes change over time. The full, sated feeling we'll experience after a big meal in the future isn't reflected in our hungry predictions in the present. Because the present is so visceral and accessible, our brains treat it as the best guide to the future, even when that leads us astray.

Section: 4, Chapter: 6

When we imagine the distant future, our brains tend to simply take our current selves and project them forward, without accounting for the ways we'll change over time.

• We imagine our current hobbies and interests will remain stable over decades.
• We imagine wanting the same foods and lifestyle forever.
• We imagine our relationships continuing with the same dynamics for years.

Just as objects in the distance look flat and simplified compared to up-close, imagined distant events look like simplistic extensions of the present. We don't fill in realistic details about how our personalities, environments, and tastes may slowly shift.

Section: 4, Chapter: 7

The human brain has a powerful built-in ability to make the best of undesirable situations - to reframe negative events in a positive light in order to maintain a reasonably happy baseline. This tendency is called the "psychological immune system."

• When rejected for a job, we decide it wasn't the right fit for us anyway.
• When a relationship ends, we focus on our ex-partner's flaws that we're now free of.
• When we fail to achieve a goal, we discover that other goals matter more to us.

By shifting our perspective, we can dampen the emotional impact of negative events and experiences. Our psychological immune system lets us feel okay about things that didn't go our way by finding a positive angle. It helps us adapt to unpleasant realities.

Section: 5, Chapter: 8

When imagining how we'll feel if a future event occurs, we fail to account for how powerfully our psychological immune system will help us accept and reframe it.

• When imagining how awful we'll feel if we lose a job, we neglect our ability to rationalize it as an opportunity for a fresh start in a better career.
• When imagining the pain of a potential breakup, we don't factor in how effectively we'll be able to find fault in our ex and move on.
• When imagining the devastation of a failed project, we can't see how quickly we'll shift focus to our other priorities.

Because we aren't consciously aware of our psychological immune system, we don't include its impact when predicting our reactions. We assume we'll feel as strongly as we do when initially imagining the event, ignoring our innate resilience. This leads us to overestimate the emotional impact of future events.

Section: 5, Chapter: 9

Just as we mispredict our future feelings, we also misremember our past feelings. Our memories of past emotional reactions are skewed by our current perspectives.

• When recalling a restaurant where we got food poisoning, we remember the overall experience as worse than it actually was in the moment.
• When reminiscing about an old relationship, we mentally exaggerate either the good or the bad aspects, painting a simpler picture than the nuanced reality.
• When describing past hardships to others, we play up the intensity for dramatic effect or to garner sympathy.

We don't do this on purpose - the distortions arise naturally in memory. We recall events through the lens of hindsight and our current goals. Just as imagination fails to capture the nuances of the future, memory fails to accurately reflect the nuances of the past.

Section: 6, Chapter: 10

Since imagination and memory are such flawed guides to how you'll feel in future situations, a more reliable approach is to find someone similar to you who is currently in the situation you're contemplating, and ask them how they feel.

• If considering a move to a new city, ask someone who recently made the same move how it's going.
• If debating graduate school, interview current students about their experiences.
• If wondering if you're ready for parenthood, spend time with friends who are new parents.

Surrogates who are actively experiencing what you're imagining have more accurate insight into its emotional impact. They aren't clouded by imaginative mispredictions. While you can never know exactly how you'll react, relying on a surrogate's experience is better than relying on your own mental simulations.

Section: 6, Chapter: 11