The Shallows: What the Internet Is Doing to Our Brains

by Nicholas Carr

The brain’s capacity is not unlimited. The passageway from perception to understanding is narrow. It takes patience and concentration to evaluate new information—to gauge its accuracy, to weigh its relevance and worth, to put it into context—and the Internet, by design, subverts patience and concentration.

When the brain is overloaded by stimuli, as it usually is when we’re peering into a network-connected computer screen, attention splinters, thinking becomes superficial, and memory suffers. We become less reflective and more impulsive. Far from enhancing human intelligence, I argue, the Internet degrades it.

The computer screen bulldozes our doubts with its bounties and conveniences. It is so much our servant that it would seem churlish to notice that it is also our master.

media aren’t just channels of information. They supply the stuff of thought, but they also shape the process of thought. And what the Net seems to be doing is chipping away my capacity for concentration and contemplation. Whether I’m online or not, my mind now expects to take in information the way the Net distributes it: in a swiftly moving stream of particles. Once I was a scuba diver in the sea of words. Now I zip along the surface like a guy on a Jet Ski.

Sometime in 2007, a serpent of doubt slithered into my info-paradise. I began to notice that the Net was exerting a much stronger and broader influence over me than my old stand-alone PC ever had. It wasn’t just that I was spending so much time staring into a computer screen. It wasn’t just that so many of my habits and routines were changing as I became more accustomed to and dependent on the sites and services of the Net. The very way my brain worked seemed to be changing. It was then that I began worrying about my inability to pay attention to one thing for more than a couple of minutes. At first I’d figured that the problem was a symptom of middle-age mind rot. But my brain, I realized, wasn’t just drifting. It was hungry.

One of the simplest yet most powerful demonstrations of how synaptic connections change came in a series of experiments that the biologist Eric Kandel performed in the early 1970s on a type of large sea slug called Aplysia. (Sea creatures make particularly good subjects for neurological tests because they tend to have simple nervous systems and large nerve cells.) Kandel, who would earn a Nobel Prize for his work, found that if you touch a slug’s gill, even very lightly, the gill will immediately and reflexively recoil. But if you touch the gill repeatedly, without causing any harm to the animal, the recoiling instinct will steadily diminish. The slug will become habituated to the touch and learn to ignore it.

“Plasticity,” says Alvaro Pascual-Leone, a top neurology researcher at Harvard Medical School, is “the normal ongoing state of the nervous system throughout the life span.” Our brains are constantly changing in response to our experiences and our behavior, reworking their circuitry with “each sensory input, motor act, association, reward signal, action plan, or [shift of] awareness.” Neuroplasticity, argues Pascual-Leone, is one of the most important products of evolution, a trait that enables the nervous system “to escape the restrictions of its own genome and thus adapt to environmental pressures, physiologic changes, and experiences.”27 The genius of our brain’s construction is not that it contains a lot of hardwiring but that it doesn’t.

It comes as no surprise that neuroplasticity has been linked to mental afflictions ranging from depression to obsessive-compulsive disorder to tinnitus. The more a sufferer concentrates on his symptoms, the deeper those symptoms are etched into his neural circuits. In the worst cases, the mind essentially trains itself to be sick. Many addictions, too, are reinforced by the strengthening of plastic pathways in the brain. Even very small doses of addictive drugs can dramatically alter the flow of neurotransmitters in a person’s synapses, resulting in long-lasting alterations in brain circuitry and function. In some cases, the buildup of certain kinds of neurotransmitters, such as dopamine, a pleasure-producing cousin to adrenaline, seems to actually trigger the turning on or off of particular genes, bringing even stronger cravings for the drug. The vital paths turn deadly.

That began to change in the latter half of the Middle Ages. The first people to demand a more precise measurement of time were Christian monks, whose lives revolved around a rigorous schedule of prayer. In the sixth century, Saint Benedict had ordered his followers to hold seven prayer services at specified times during the day. Six hundred years later, the Cistercians gave new emphasis to punctuality, dividing the day into a regimented sequence of activities and viewing any tardiness or other waste of time to be an affront to God. Spurred by the need for temporal exactitude, monks took the lead in pushing forward the technologies of timekeeping. It was in the monastery that the first mechanical clocks were assembled, their movements governed by the swinging of weights, and it was the bells in the church tower that first sounded the hours by which people would come to parcel out their lives.

The mechanical clock changed the way we saw ourselves. And like the map, it changed the way we thought. Once the clock had redefined time as a series of units of equal duration, our minds began to stress the methodical mental work of division and measurement. We began to see, in all things and phenomena, the pieces that composed the whole, and then we began to see the pieces of which the pieces were made. Our thinking became Aristotelian in its emphasis on discerning abstract patterns behind the visible surfaces of the material world. The clock played a crucial role in propelling us out of the Middle Ages and into the Renaissance and then the Enlightenment.

What Nietzsche sensed as he typed his words onto the paper clamped in his writing ball—that the tools we use to write, read, and otherwise manipulate information work on our minds even as our minds work with them—is a central theme of intellectual and cultural history. As the stories of the map and the mechanical clock illustrate, intellectual technologies, when they come into popular use, often promote new ways of thinking or extend to the general population established ways of thinking that had been limited to a small, elite group. Every intellectual technology, to put it another way, embodies an intellectual ethic, a set of assumptions about how the human mind works or should work. The map and the clock shared a similar ethic. Both placed a new stress on measurement and abstraction, on perceiving and defining forms and processes beyond those apparent to the senses.

The intellectual ethic of a technology is rarely recognized by its inventors. They are usually so intent on solving a particular problem or untangling some thorny scientific or engineering dilemma that they don’t see the broader implications of their work. The users of the technology are also usually oblivious to its ethic. They, too, are concerned with the practical benefits they gain from employing the tool. Our ancestors didn’t develop or use maps in order to enhance their capacity for conceptual thinking or to bring the world’s hidden structures to light. Nor did they manufacture mechanical clocks to spur the adoption of a more scientific mode of thinking. Those were by-products of the technologies. But what by-products! Ultimately, it’s an invention’s intellectual ethic that has the most profound effect on us. The intellectual ethic is the message that a medium or other tool transmits into the minds and culture of its users.

THE MAP AND clock changed language indirectly, by suggesting new metaphors to describe natural phenomena. Other intellectual technologies change language more directly, and more deeply, by actually altering the way we speak and listen or read and write. They might enlarge or compress our vocabulary, modify the norms of diction or word order, or encourage either simpler or more complex syntax. Because language is, for human beings, the primary vessel of conscious thought, particularly higher forms of thought, the technologies that restructure language tend to exert the strongest influence over our intellectual lives. As the classical scholar Walter J. Ong put it, “Technologies are not mere exterior aids but also interior transformations of consciousness, and never more than when they affect the word.”18 The history of language is also a history of the mind.

Socrates, it’s clear, shares Thamus’s view. Only “a simple person,” he tells Phaedrus, would think that a written account “was at all better than knowledge and recollection of the same matters.” Far better than a word written in the “water” of ink is “an intelligent word graven in the soul of the learner” through spoken discourse. Socrates grants that there are practical benefits to capturing one’s thoughts in writing—“as memorials against the forgetfulness of old age”—but he argues that a dependence on the technology of the alphabet will alter a person’s mind, and not for the better. By substituting outer symbols for inner memories, writing threatens to make us shallower thinkers, he says, preventing us from achieving the intellectual depth that leads to wisdom and true happiness.

Readers didn’t just become more efficient. They also became more attentive. To read a long book silently required an ability to concentrate intently over a long period of time, to “lose oneself” in the pages of a book, as we now say. Developing such mental discipline was not easy. The natural state of the human brain, like that of the brains of most of our relatives in the animal kingdom, is one of distractedness. Our predisposition is to shift our gaze, and hence our attention, from one object to another, to be aware of as much of what’s going on around us as possible.

THE NET DIFFERS from most of the mass media it replaces in an obvious and very important way: it’s bidirectional. We can send messages through the network as well as receive them. That’s made the system all the more useful. The ability to exchange information online, to upload as well as download, has turned the Net into a thoroughfare for business and commerce. With a few clicks, people can search virtual catalogues, place orders, track shipments, and update information in corporate databases. But the Net doesn’t just connect us with businesses; it connects us with one another. It’s a personal broadcasting medium as well as a commercial one.

A page of online text viewed through a computer screen may seem similar to a page of printed text. But scrolling or clicking through a Web document involves physical actions and sensory stimuli very different from those involved in holding and turning the pages of a book or a magazine. Research has shown that the cognitive act of reading draws not just on our sense of sight but also on our sense of touch. It’s tactile as well as visual. “All reading,” writes Anne Mangen, a Norwegian literary studies professor, is “multi-sensory.” There’s “a crucial link” between “the sensory-motor experience of the materiality” of a written work and “the cognitive processing of the text content.” 22 The shift from paper to screen doesn’t just change the way we navigate a piece of writing. It also influences the degree of attention we devote to it and the depth of our immersion in it.

The searchability of online works also represents a variation on older navigational aids such as tables of contents, indexes, and concordances. But here, too, the effects are different. As with links, the ease and ready availability of searching make it much simpler to jump between digital documents than it ever was to jump between printed ones. Our attachment to any one text becomes more tenuous, more provisional. Searches also lead to the fragmentation of online works. A search engine often draws our attention to a particular snippet of text, a few words or sentences that have strong relevance to whatever we’re searching for at the moment, while providing little incentive for taking in the work as a whole. We don’t see the forest when we search the Web. We don’t even see the trees. We see twigs and leaves. As companies like Google and Microsoft perfect search engines for video and audio content, more products are undergoing the fragmentation that already characterizes written works.

Our use of the Internet involves many paradoxes, but the one that promises to have the greatest long-term influence over how we think is this one: the Net seizes our attention only to scatter it. We focus intensively on the medium itself, on the flickering screen, but we’re distracted by the medium’s rapid-fire delivery of competing messages and stimuli. Whenever and wherever we log on, the Net pre-sents us with an incredibly seductive blur. Human beings “want more information, more impressions, and more complexity,” writes Torkel Klingberg, the Swedish neuroscientist. We tend to “seek out situations that demand concurrent performance or situations in which [we] are overwhelmed with information.”2 If the slow progression of words across printed pages dampened our craving to be inundated by mental stimulation, the Net indulges it. It returns us to our native state of bottom-up distractedness, while presenting us with far more distractions than our ancestors ever had to contend with.

The depth of our intelligence hinges on our ability to transfer information from working memory to long-term memory and weave it into conceptual schemas. But the passage from working memory to long-term memory also forms the major bottleneck in our brain. Unlike long-term memory, which has a vast capacity, working memory is able to hold only a very small amount of information. In a renowned 1956 paper, “The Magical Number Seven, Plus or Minus Two,” Princeton psychologist George Miller observed that working memory could typically hold just seven pieces, or “elements,” of information. Even that is now considered an overstatement.

The Net is, by design, an interruption system, a machine geared for dividing attention. That’s not only a result of its ability to display many different kinds of media simultaneously. It’s also a result of the ease with which it can be programmed to send and receive messages.

frequent interruptions scatter our thoughts, weaken our memory, and make us tense and anxious. The more complex the train of thought we’re involved in, the greater the impairment the distractions cause.

In addition to flooding our working memory with information, the juggling imposes what brain scientists call “switching costs” on our cognition. Every time we shift our attention, our brain has to reorient itself, further taxing our mental resources. As Maggie Jackson explains in Distracted, her book on multitasking, “the brain takes time to change goals, remember the rules needed for the new task, and block out cognitive interference from the previous, still-vivid activity.”

The findings, said Liu, indicate that “the digital environment tends to encourage people to explore many topics extensively, but at a more superficial level,” and that “hyperlinks distract people from reading and thinking deeply.” One of the participants in the study told Liu, “I find that my patience with reading long documents is decreasing. I want to skip ahead to the end of long articles.” Another said, “I skim much more [when reading] html pages than I do with printed materials.” It’s quite clear, Liu concluded, that with the flood of digital text pouring through our computers and phones, “people are spending more time on reading” than they used to. But it’s equally clear that it’s a very different kind of reading.

There’s nothing wrong with browsing and scanning, or even power-browsing and power-scanning. We’ve always skimmed newspapers more than we’ve read them, and we routinely run our eyes over books and magazines in order to get the gist of a piece of writing and decide whether it warrants more thorough reading. The ability to skim text is every bit as important as the ability to read deeply. What is different, and troubling, is that skimming is becoming our dominant mode of reading. Once a means to an end, a way to identify information for deeper study, scanning is becoming an end in itself—our preferred way of gathering and making sense of information of all sorts. We’ve reached the point where a Rhodes Scholar like Florida State’s Joe O’Shea—a philosophy major, no less—is comfortable admitting not only that he doesn’t read books but that he doesn’t see any particular need to read them. Why bother, when you can Google the bits and pieces you need in a fraction of a second? What we’re experiencing is, in a metaphorical sense, a reversal of the early trajectory of civilization: we are evolving from being cultivators of personal knowledge to being hunters and gatherers in the electronic data forest.

We’re not smarter than our parents or our parents’ parents. We’re just smart in different ways. And that influences not only how we see the world but also how we raise and educate our children. This social revolution in how we think about thinking explains why we’ve become ever more adept at working out the problems in the more abstract and visual sections of IQ tests while making little or no progress in expanding our personal knowledge, bolstering our basic academic skills, or improving our ability to communicate complicated ideas clearly. We’re trained, from infancy, to put things into categories, to solve puzzles, to think in terms of symbols in space.

In his 1993 book Technopoly, Neil Postman distilled the main tenets of Taylor’s system of scientific management. Taylorism, he wrote, is founded on six assumptions: “that the primary, if not the only, goal of human labor and thought is efficiency; that technical calculation is in all respects superior to human judgment; that in fact human judgment cannot be trusted, because it is plagued by laxity, ambiguity, and unnecessary complexity; that subjectivity is an obstacle to clear thinking; that what cannot be measured either does not exist or is of no value; and that the affairs of citizens are best guided and conducted by experts.”11 What’s remarkable is how well Postman’s summary encapsulates Google’s own intellectual ethic. Only one tweak is required to bring it up to date.

GOOGLE WAS BORN of an analogy—Larry Page’s analogy. The son of one of the pioneers of artificial intelligence, Page was surrounded by computers from an early age—he recalls being “the first kid in my elementary school to turn in a word-processed document”16—and went on to study engineering as an undergraduate at the University of Michigan. His friends remember him as being ambitious, smart, and “nearly obsessed with efficiency.”17 While serving as president of Michigan’s engineering honor society, he spearheaded a brash, if ultimately futile, campaign to convince the school’s administrators to build a monorail through the campus. In the fall of 1995, Page headed to California to take a prized spot in Stanford University’s doctoral program in computer science. Even as a young boy, he had dreamed of creating a momentous invention, something that “would change the world.”18 He knew there was no better place than Stanford, Silicon Valley’s frontal cortex, to make the dream come true.

But Google, as the supplier of the Web’s principal navigational tools, also shapes our relationship with the content that it serves up so efficiently and in such profusion. The intellectual technologies it has pioneered promote the speedy, superficial skimming of information and discourage any deep, prolonged engagement with a single argument, idea, or narrative. “Our goal,” says Irene Au, “is to get users in and out really quickly. All our design decisions are based on that strategy.”21 Google’s profits are tied directly to the velocity of people’s information intake. The faster we surf across the surface of the Web—the more links we click and pages we view—the more opportunities Google gains to collect information about us and to feed us advertisements.

Because the sales of complementary products rise in tandem, a company has a strong strategic interest in reducing the cost and expanding the availability of the complements to its main product. It’s not too much of an exaggeration to say that a company would like all complements to be given away. If hot dogs were free, mustard sales would skyrocket. It’s this natural drive to reduce the cost of complements that, more than anything else, explains Google’s business strategy. Nearly everything the company does is aimed at reducing the cost and expanding the scope of Internet use. Google wants information to be free because, as the cost of information falls, we all spend more time looking at computer screens and the company’s profits go up.

The irony in Google’s effort to bring greater efficiency to reading is that it undermines the very different kind of efficiency that the technology of the book brought to reading—and to our minds—in the first place. By freeing us from the struggle of decoding text, the form that writing came to take on a page of parchment or paper enabled us to become deep readers, to turn our attention, and our brain power, to the interpretation of meaning. With writing on the screen, we’re still able to decode text quickly—we read, if anything, faster than ever—but we’re no longer guided toward a deep, personally constructed understanding of the text’s connotations. Instead, we’re hurried off toward another bit of related information, and then another, and another. The strip-mining of “relevant content” replaces the slow excavation of meaning.

WHAT DETERMINES WHAT we remember and what we forget? The key to memory consolidation is attentiveness. Storing explicit memories and, equally important, forming connections between them requires strong mental concentration, amplified by repetition or by intense intellectual or emotional engagement. The sharper the attention, the sharper the memory. “For a memory to persist,” writes Kandel, “the incoming information must be thoroughly and deeply processed. This is accomplished by attending to the information and associating it meaningfully and systematically with knowledge already well established in memory.”35 If we’re unable to attend to the information in our working memory, the information lasts only as long as the neurons that hold it maintain their electric charge—a few seconds at best. Then it’s gone, leaving little or no trace in the mind.

The influx of competing messages that we receive whenever we go online not only overloads our working memory; it makes it much harder for our frontal lobes to concentrate our attention on any one thing. The process of memory consolidation can’t even get started. And, thanks once again to the plasticity of our neuronal pathways, the more we use the Web, the more we train our brain to be distracted—to process information very quickly and very efficiently but without sustained attention. That helps explain why many of us find it hard to concentrate even when we’re away from our computers. Our brains become adept at forgetting, inept at remembering. Our growing dependence on the Web’s information stores may in fact be the product of a self-perpetuating, self-amplifying loop.

The experiment, say the scholars, indicates that the more distracted we become, the less able we are to experience the subtlest, most distinctively human forms of empathy, compassion, and other emotions. “For some kinds of thoughts, especially moral decision-making about other people’s social and psychological situations, we need to allow for adequate time and reflection,” cautions Mary Helen Immordino-Yang, a member of the research team. “If things are happening too fast, you may not ever fully experience emotions about other people’s psychological states.”37 It would be rash to jump to the conclusion that the Internet is undermining our moral sense. It would not be rash to suggest that as the Net reroutes our vital paths and diminishes our capacity for contemplation, it is altering the depth of our emotions as well as our thoughts.