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Harvard researchers explain how our brains skim information—and how to actually get people’s attention

Science suggests that while skimming is faster than reading, it also leaves us susceptible to missing information.

Harvard researchers explain how our brains skim information—and how to actually get people’s attention
[Source photo: sah/Getty Images]

Once you have a deeper insight into what goes on inside a reader’s brain, you can appreciate the immense challenge of breaking through all that clutter and noise. Fortunately, you don’t have to guess how to go about it! We have drawn on a large body of professional experience and academic research (along with personal insights) to provide proven guidance.

The first step to writing effectively is understanding the ways in which limited time and attention affect how busy people read. Then you can begin to work your way past the fundamental hurdles that determine whether an idea in your head will find a home in someone else’s head: the filters that decide whether, when, and how carefully to read the messages they receive.

Every time a reader encounters a written communication—even something as short as an email, a text, a Slack message, or social media post—they go through a four-stage process:

• First, they must decide whether to engage with it at all.

• Second, if they decide to engage, they then must decide when to engage. Sometimes the decision to engage leads to a decision to engage later.

• Third, once they do engage, they must decide how much time and attention to allocate to reading the message.

• Fourth, if they read something that requires a response, they must decide whether to respond or react.

These decisions are often nearly instantaneous, performed with little or no conscious thought. Rarely do we carefully deliberate about each stage. But a tremendous amount of mental processing happens during that tiny blip of time. Our job as effective writers is to navigate each of the four critical rounds in that brief but daunting process.


When readers receive a communication, they automatically put it to a test: Is this message worth my time? Should I even bother to engage with it?

Economists describe this type of decision-making as “expected utility maximization.” When making decisions between alternatives, people weigh the expected costs and benefits of all possible choices; then they choose the option that maximizes the expected benefits and minimizes the expected costs. People consider their time precious, so the threshold to engage can be quite high. In a recent survey we conducted with around 1,800 working professionals, they estimated that they delete about half of the emails they receive without reading them.

That is a striking result when you think about it from a cognitive perspective. Busy readers routinely decide how valuable a message is without actually reading it! And working professionals are hardly the only ones making snap judgments based on limited information. We all do the same basic thing, all the time, using mental shortcuts that simplify decision-making.

Decision researchers call these mental shortcuts heuristics, but for simplicity, we’ll call them rules of thumb. One common rule of thumb is that, when faced with a lot of options, we pick the first one that seems good enough (sometimes called “satisficing”), rather than expending the effort to seek out the absolutely best measured option. Think about how many movies are available on Netflix. It would take days to search through every available option to find the one that will maximize your enjoyment. The “good enough” rule allows you to cut the task down to a minute or two. Rules of thumb help us navigate complex, information-rich decisions—from choosing Netflix shows to sorting through our email inbox.

Readers often infer the value of a communication from its “envelope,” the readily available information surrounding a communication that signals its content. For an email, this information might be the sender or subject line. For an office memo, it might be the title. For a traditional letter, it might be the return address or the format of the physical envelope. (In essence, we really do judge a book by its cover.) Readers read these clues and then apply rules of thumb to determine whether or not to engage. We might prioritize messages from someone we are close to, such as a friend or family member. Conversely, we might choose to ignore messages from senders we don’t recognize, especially if the rest of the available cues make those messages appear irrelevant.

Estimating the expected benefits of a received message is only half of the calculation that busy readers make when deciding whether to engage with a communication. They also consider the costs involved: How much time and effort will be required to engage? Here, too, people apply rules of thumb to make this assessment. Their initial estimate of costs (measured both in time and effort) heavily influences readers’ decisions to engage. Most notably, they are more likely to engage with messages that are short or that appear easy to navigate because they seem like they will require less time, attention, and effort to read.

The preference for short, easy messages makes obvious sense, but busy readers short on time and attention can also be myopic, sometimes even illogical: They tend to heavily prioritize the present over the future. Have you ever decided that next week you’ll start saving money or dieting or exercising? And then when next week arrived, you decided that you would really start . . . the next week? Yeah, we do it, too. Most of us prefer doing enjoyable, pleasant, easy, and gratifying things now, and push off less pleasant, more difficult things until later. Even though the ultimate cost of those will be just the same, it feels like we are coming out ahead by not paying the cost right now.


Revisiting the Netflix question from a cost perspective, imagine that you have narrowed down the vast set of movie offerings to just a couple options. How do you choose which one to watch right now? The movies we want to watch often fall into two categories. There are the ones we want to watch because we think they’ll be enjoyable, such as entertaining action movies or romantic comedies, and the ones we feel like we should watch because we think they’ll be educational or good for us, like award-winning documentaries or foreign-language films.

Research that we conducted with our colleagues has shown that people tend to watch the more enjoyable movies first, before getting around to the “good for us” options. Other studies have examined “want” versus “should” decisions in professional contexts, and confirmed that people tend to procrastinate before turning to tasks that are more difficult and less enjoyable. When people are asked to complete a mixed set of easy and hard tasks, they typically tackle the easy tasks first. The pattern holds true even if people are offered financial incentives for prioritizing the hard ones.

Our tendency to privilege the present over the future means that we are often willing to pay a price in order to enjoy pleasant things right now. A classic study of this tendency asked people whether they would prefer to receive “$100 right now” or “$101 in one week.” Most people chose the desirable thing (receiving $100) right now, even though it meant forgoing a slightly more desirable thing in the near future. Getting an extra 1% in one week is equivalent to earning 68% interest over one year, yet participants in the experiment typically decided they’d rather not wait one week for the additional money.

Just as we forgo benefits to have good things now, we are also willing to incur costs to push unpleasant things off until later. In one of our student surveys, participants reported that they would rather sit in traffic for thirty-one minutes a week from now than sit for thirty minutes right now, even knowing that postponing will end up costing them an extra minute of unpleasantness. If you write something that your intended reader thinks is going to be an unpleasant slog, you can bet that they are going to put off reading it until . . . later.

The tendency to privilege the present over the future is hardwired into us. Researchers using magnetic resonance imaging (MRI) scans observed that particular parts of the brain associated with immediate rewards (the limbic reward-related regions) activate when we consider options that include desirable outcomes now, but stay mostly dormant when considering options that only include desirable outcomes later. Similar behavior has been observed across the human development cycle and even across different animal species, including rats, chimpanzees, and birds, to name a few.

All of these cost-benefit calculations relate directly to the ways in which we engage with communications we receive. Busy readers are likely to prioritize messages they think can be dealt with easily and quickly, because they seem more enjoyable (or at least less awful). Conversely, readers will tend to avoid messages that appear long and time-consuming, pushing them off into the future. Our surveys clearly show these responses: In one instance, a full 99% of working professionals in a class we taught said they would respond first to a message that they perceived to be easier to deal with than to one that appeared more difficult.


Spoiler alert: Everyone skims.

Busy readers aim to extract as much value as possible from a communication with as little time and attention as possible. To achieve this, they don’t always read linearly, line by line. They vary how they read to suit their goals. They may closely read one section, skim another, and jump around in yet another, searching for specific information that they consider relevant. In the language of economics theory: Busy readers maximize their expected utility by continuously trying to predict whether the value of spending another second reading the message is greater than the benefit of spending that time and attention on something else.

Readers don’t intentionally think, “Okay, time to maximize my expected utility!” We simply move on when we get bored or distracted. Our conscious focus is constantly at risk of distraction. We can learn a lot of valuable information in the first few seconds spent reading a message, but soon we reach the point of diminishing returns—at least, that is our common expectation. Each additional second of our attention tends to yield less information, especially once we have surmised the gist of the message. From then on, our reading time becomes progressively less valuable. Busy readers have a low threshold for moving on: As soon as the expected value of the next second spent reading is lower than the value of whatever else we would be doing instead, we stop.

In general, reading for utility is an efficient strategy for extracting as much information as possible while expending as little time and attention as possible. But there’s a problem: The value of some messages may be realized only if they’re read in full. The whole may be greater than the sum of the individual parts.

Think about an email you might receive from a friend recounting a humorous encounter he had while at a Philadelphia Eagles football game. He was in the parking lot outside Lincoln Financial Field, eating hoagies and catching up with friends. An older couple walked by and struck up a conversation about the Eagles’ defensive players and whether they were good enough to win the championship that year. After a few minutes, just as your friend was about to head into the stadium, he realized that the older couple were your parents, who by chance were visiting from Arizona that week. Out of thirty thousand fans there, what are the odds? If you had stopped reading the second you understood the gist of the message—that your friend went to a Philadelphia Eagles game—you would have missed the twist ending, which, really, was the entire point of the message.

Skimming also leaves readers vulnerable to misssing key information. Did you notice that “missing” was misspelled in the previous sentence? If you did, you were likely reading closely, which we appreciate—thank you! Close reading means you won’t miss as much, but it also requires a lot more of your time and attention. On the other hand, we fully understand and expect that many of you will skim this chapter. You’ll make it through much more quickly that way, but you will likely misss some of the finer details. (Did you catch it that time?)

Psychologists Keith Rayner and Monica Castelhano have mapped how our eyes move when reading closely versus when we are skimming, as the following image illustrates. The circles indicate where participants’ eyes focus and pause; those locations are called “fixations.” The lines indicate where the eyes move during the time between fixations. During close reading, the eyes move from word to word in sequence. But when skimming, the eyes have fewer fixations and jump across lines.

Skimming often involves skipping words, phrases, and even paragraphs. It also often involves jumping forward in anticipation, and jumping backwards to review or find something initially missed. We take in words out of order, and skip over a lot of them completely. That is why skimming is faster than reading, but also why it leaves us susceptible to missing information.

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Todd Rogers is Professor of Public Policy at Harvard University, where he has won teaching awards for the past seven consecutive years. He is a behavioral scientist and co-founder of the Analyst Institute and Everyday Labs. Jessica Lasky-Fink is the Research Director at The People Lab, based at the Harvard Kennedy School. Her research focuses on improving the delivery of government programs and services. More

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