For those who dread a colonoscopy or a root canal so much that they avoid it altogether, scientists have good news.

The first study ever to look at where sensations of dread arise in the brain finds that contrary to what is widely believed, dread does not involve fear and anxiety in the moment of an unpleasant event. Instead, it derives from the attention that people devote beforehand to what they think will be extremely unpleasant.

So the solution to dread, the researchers say, is self-distraction.

"We sort of knew that things like self-hypnosis help relieve dread, but now we know why," said Dr. Gregory S. Berns, a professor of psychiatry and behavioral sciences at Emory University, who led the study.

The research, being published today in the journal Science, is "terrific, " said a leading expert on brain imaging, Dr. Read Montague, a professor of neuroscience at Baylor College of Medicine who was not involved in the study. It demonstrates that the brain "assigns a cost to waiting for something bad, so that the bad thing is worse when it's delayed farther in the future," Dr. Montague said.

"Hence," he said, "the 'let's get it over with' bit when we're at the doctor's office waiting to get a shot."

The research also sheds light on economic behavior, said George Loewenstein, a behavioral economist at Carnegie Mellon University. According to standard economic models of human behavior, choosing more pain in the short run is irrational, Dr. Loewenstein said: if you know something bad is going to happen, you should postpone it as long as possible, and if something good is going to happen, you should want it right away.

In real life, people often do the exact opposite, he said. They delay gratification to savor a sweet sense of anticipation, and accelerate punishment just to get it over with. The new study sheds light, he said, on how the act of waiting can be used to describe economic behavior more accurately.

For the study, Dr. Berns put 32 people into a brain scanner and applied brief electric shocks to the tops of their left feet. After their maximum pain threshold was determined, meaning the most pain they could withstand, they were each presented a series of 96 cues. Each cue stated how much voltage they were about to experience and how long they would have to wait for it. For example, one cue might say they were about to receive 60 percent of their maximum pain after 27 seconds. Another might warn of a 30 percent maximum shock after 9 seconds.

Next the subjects were given options involving various combinations of voltage and how long they had to wait for it . For example, they could choose between getting 90 percent of their maximum voltage after three seconds or 60 percent after 27 seconds. Then they received the chosen shock to the foot.

The scanner detected the brain activity involved in waiting for shocks, providing a road map for understanding the dread response.

Twenty-three of the people, termed "mild dreaders," chose as short a delay as possible for any given voltage but were not willing to accept more pain just to get it over with, Dr. Berns said. The nine others, called "extreme dreaders," always took the highest voltage if it was sooner rather than later. They gladly accepted more pain to reduce their dread time.

In comparing the brain scans of both groups, Dr. Berns found only one difference. During the waiting period, extreme dreaders showed high activity in a part of the brain's so-called pain matrix that involves attention.

The pain matrix is a set of brain regions that become active when people experience pain, Dr. Berns said. Parts of it deal with sensing the body, while other regions are involved in intuition, emotions, fear or attention. Extreme dreaders, he said, deploy more attention to their soon-to-be-shocked foot than do mild dreaders. Above all else, dread involves attention to unpleasant things to come, making it quite different from anxiety or fear.

When it comes to a root canal or a colonoscopy, it is not really the procedures themselves that people dread, but the waiting time, Dr. Berns said. For extreme dreaders, finding distraction is probably the best way to cope.

MY younger sister has just arrived in New Orleans for the summer after her freshman year at Yale. She will be consuming daily snowballs, the local icy treat, to ward off the heat, volunteering to help clean up neighborhoods damaged by Hurricane Katrina and working part time, for pay, at both a literary festival and a local restaurant. Meanwhile, most of her friends from college are headed for the new standard summer experience: the unpaid internship.

Instead of starting out in the mailroom for a pittance, this generation reports for business upstairs without pay. A national survey by Vault, a career information Web site, found that 84 percent of college students in April planned to complete at least one internship before graduating. Also according to Vault, about half of all internships are unpaid.

I was an unpaid intern at a newspaper from March 2002, my senior year, until a few months after graduation. I took it for granted, as most students do, that working without pay was the best possible preparation for success; parents usually agree to subsidize their offspring's internships on this basis. But what if we're wrong?

What if the growth of unpaid internships is bad for the labor market and for individual careers?

Let's look at the risks to the lowly intern. First there are opportunity costs. Lost wages and living expenses are significant considerations for the two-thirds of students who need loans to get through college. Since many internships are done for credit and some even cost money for the privilege of placement overseas or on Capitol Hill, those students who must borrow to pay tuition are going further into debt for internships.

Second, though their duties range from the menial to quasi-professional, unpaid internships are not jobs, only simulations. And fake jobs are not the best preparation for real jobs.

Long hours on your feet waiting tables may not be particularly edifying, but they teach you that work is a routine of obligation, relieved by external reward, where you contribute value to a larger enterprise. Newspapers and business magazines are full of articles expressing exasperation about how the Millennial-generation employee supposedly expects work to be exciting immediately, wears flip-flops to the office and has no taste for dues-paying. However true this stereotype may be, the spread of the artificially fun internship might very well be adding fuel to it.

By the same token, internships promote overidentification with employers: I make sacrifices to work free, therefore I must love my work. A sociologist at the University of Washington, Gina Neff, who has studied the coping strategies of interns in communications industries, calls the phenomenon "performative passion." Perhaps this emotion helps explain why educated workers in this country are less and less likely to organize, even as full-time jobs with benefits go the way of the Pinto.

Although it's not being offered this year, the A.F.L.-C.I.O.'s Union Summer internship program, which provides a small stipend, has shaped thousands of college-educated career organizers. And yet interestingly, the percentage of young workers who hold an actual union card is less than 5 percent, compared with an overall national private-sector union rate of 12.5 percent. How are twentysomethings ever going to win back health benefits and pension plans when they learn to be grateful to work for nothing?

So an internship doesn't teach you everything you need to know about coping in today's working world. What effect does it have on the economy as a whole?

The Bureau of Labor Statistics does not identify interns or track the economic impact of unpaid internships. But we can do a quick-and-dirty calculation: according to Princeton Review's "Internship Bible," there were 100,000 internship positions in 2005. Let's assume that out of those, 50,000 unpaid interns are employed full time for 12 weeks each summer at an average minimum wage of $5.15 an hour. That's a nearly $124 million yearly contribution to the welfare of corporate America.

In this way, unpaid interns are like illegal immigrants. They create an oversupply of people willing to work for low wages, or in the case of interns, literally nothing. Moreover, a recent survey by Britain's National Union of Journalists found that an influx of unpaid graduates kept wages down and patched up the gaps left by job cuts.

There may be more subtle effects as well. In an information economy, productivity is based on the best people finding the jobs best suited for their talents, and interns interfere with this cultural capitalism. They fly in the face of meritocracy — you must be rich enough to work without pay to get your foot in the door. And they enhance the power of social connections over ability to match people with desirable careers. A 2004 study of business graduates at a large mid-Atlantic university found that the completion of an internship helped people find jobs faster but didn't increase their confidence that those jobs were a good fit.

With all this said, the intern track is not coming to an end any time soon. More and more colleges are requiring some form of internship for graduation. Still, if you must do an internship, research shows you will get more out of it if you find a paid one.

A 1998 survey of nearly 700 employers by the Institute on Education and the Economy at Columbia University's Teachers College found: "Compared to unpaid internships, paid placements are strongest on all measures of internship quality. The quality measures are also higher for those firms who intend to hire their interns." This shouldn't be too surprising — getting hired and getting paid are what work, in the real world, is all about.

Anya Kamenetz, a columnist for The Village Voice, is the author of "Generation Debt."

Everyone knows that talking about your feelings is supposed to be good for you. In part, that's probably why psychotherapy is widely viewed as a healthy pursuit. Conventional wisdom has it that self-knowledge is always a boon, and, like wealth, you can never have too much of it.

That's what I thought until I met Helen.

Helen was a successful 52-year-old professional who had been married for 30 years. After watching "The Celebration," a movie in which the family patriarch is publicly unmasked as a sexual predator by his children, Helen recovered what she believed were memories of sexual abuse by her father.

Over the course of several months, she felt depressed and angry and decided to start psychotherapy for the first time. Her therapist recommended twice-weekly sessions and encouraged her to discuss her childhood and memories of sexual abuse.

She became more depressed and anxious during the initial treatment, hardly unexpected given the traumatic material she had to deal with. But then something alarming began to happen.

Helen began to abuse alcohol, something she had never done before, and to cut her wrists superficially, an old behavior that she had stopped in her 20's.

Helen was confused. If therapy was supposed to help her, why did she feel so much worse? What could explain the fact that this previously high-performing professional woman had become a serious alcohol abuser who was cutting her wrists several times a week with a razor?

The problem was that Helen had what psychiatrists call borderline personality disorder, and therapy had encouraged a process of self-exploration that proved toxic to her.

She did not have the psychological resources to deal with the intense emotions that this kind of therapy unleashed.

Borderline patients frequently use alcohol or drugs to try to stabilize their overly reactive moods, and they often injure themselves to relieve unbearable psychic pain.

In hindsight, it's easy to see that this was just the wrong treatment for this particular patient. Yet even when she was given a more supportive treatment, aimed at helping her cope rather than delve into her feelings, she still floundered and didn't function nearly as well as she did before having any therapy.

It will sound heretical coming from a psychiatrist, but there are some patients who feel worse and get worse when they are in psychotherapy. For some, the problem is getting the wrong type of treatment; for others, it may be the relationship with the therapist that is problematic, regardless of the specific treatment.

In an analysis of psychotherapy studies, Dr. Michael Lambert, a professor of psychology at Brigham Young University and a well-known expert in psychotherapy research, found that about 5 percent to 10 percent of patients deteriorated with psychotherapy.

This is not a trivial problem considering that 3.5 percent of all Americans were in psychotherapy each year from 1987 to 1997, according to a 2002 study published in The American Journal of Psychiatry by Dr. Mark Olfson of the College of Physicians and Surgeons of Columbia.

Although we are not very good at predicting which patients are likely to get worse with treatment, it's not that hard to spot them once they are in therapy and things aren't going well.

A few years back, one of my residents was treating a young man in psychotherapy who had great difficulty deciding what he wanted to do with his life.

He wasn't depressed, but he was a very passive person.

It became clear that the patient was using the treatment not to understand his passivity, but to indulge it; he enjoyed talking about what he should do, but made no steps outside of therapy despite many attempts to address his behavior. We stopped his psychotherapy and referred him for vocational counseling.

The possible benefits of no treatment go beyond just patients who get worse in therapy. Some patients have been in psychotherapy for so long that it isn't clear what the advantage of treatment is; in some of these cases, stopping therapy gives patients a chance to discover that they might do fine without it.

Others might seek treatment during a crisis or when they are grief-stricken. As painful as these situations can be, if people are generally healthy and have good social supports, they are likely just to feel better with time and probably don't need any treatment at all.

At first blush, it might sound paradoxical — even uncaring — but sometimes the best treatment is no treatment at all.

I have the television tuned to a news channel as I write this, my voice mail box is spilling its contents over the speakerphone, and I pause occasionally to flip screens on my computer to check e-mail messages. Still, something feels missing. I think of the executive who positioned his office computer above a treadmill, so he could walk constantly, keeping fit as he ran a business.

The pursuit of maximum moments drives many a multitasking life and an often-distracted mind. Cabbies chat away on the cellphone, even though laws in many places forbid it. Pedestrians text-message, leaving it to others to navigate around them.

Studies show that people may pack the equivalent of 31 hours of activities into a 24-hour day by doing several things at once. That's impressive, although I wonder if any study has figured out how to count the tasks still being tackled during sleep, as the strands of things done too hastily or inattentively deprive us of real rest.

We think of America as a sleep-deprived nation, but we are becoming deep-thought deprived, too. A closed door does not stop interruptions, because we are packing the weapons that can shatter concentration or quiet contemplation. Our fingers are always on a button.

Multitasking did not begin with computers, cellphones or other wireless technology, of course, although they have kicked it up to progressively new levels of complexity. Before those gadgets came along, the TV tray encouraged people to choose entertainment or the evening news over the dinner table and conversation. Radios were put in homes and then cars, helping to fill the dead air that can accompany housework and long rides. We seem afraid to be alone with our thoughts.

I have been a determined multitasker for as long as I can remember, insisting on doing my homework before the television. It did not seem to hurt my grades, but I will never know. Now I am loath to completely shut off connectors to those outside my immediate purview. I might miss something, or someone might miss me. And that would be disastrous. Wouldn't it?

LOS ANGELES

AS he puts the finishing touches on "Superman Returns," the director Bryan Singer is thinking about bathrooms.

During a screening of one of the "Lord of the Rings" movies, Mr. Singer noticed how many kids in the audience made a mad dash for the bathrooms during bits of dialogue-heavy exposition. "It was like a stampede," he said in recent phone interview. A little while later, during one of the movie's prolonged battle sequences, he noticed adults making a similar exodus. Mr. Singer predicts a similar shuffling when his "Superman" lands in theaters June 30.

"I'd like to think this movie is entirely universal," he said. "But I know there will be bathroom moments for the kids and bathroom moments for adults."

Such is the strange dynamic faced by filmmakers during what has become the most demographically challenging part of the annual film calendar: those supposedly carefree months from early May to Labor Day.

At year's end sober-minded Oscar movies, the "Capotes" and "Munichs," compete for grown-ups, while the likes of "Chicken Little" and "Cheaper by the Dozen" fight for the children. In the early months, once again, adult pictures like "United 93" coexist at the multiplex with youth fare like "Hoot." But summer, when big studios place their heaviest bets, has become the preserve of films made for neither the old nor the young, but rather for the child in the adult and the adult in the child. That exercise is far more complex, in its way, than telling a love story about gay cowboys, or creating R-rated horror. It involves finding the peculiar spot at which couples on a date and parents who may seldom share a home-cooked meal with their children will converge, all of them, on a single experience.

Within Hollywood, the current jargon says a summer blockbuster should play in "all four quadrants": that is, across the age spectrum. "There's got to be something for everybody," explained Jeff Blake, vice chairman of Sony Pictures Entertainment, which famously managed that trick with its "Spider-Man" films.

More striking, though, is the degree to which summer films like this year's "X-Men 3" or Mr. Singer's "Superman Returns" seem increasingly to define a new kind of cultural space, in which traditional notions about age mean little.

Such pictures appear to sit comfortably with an ascendancy of adults who act and think more like kids than conventional adults. These are the not-quite-grown-ups — one could call them "rejuveniles" — who delay marriage and parenthood, the better to maintain lives of fun and flexibility, who then bond and play with their own offspring in ways their parents would find ridiculous, and whose consumer choices have expanded the market for everything from micromini cars to gourmet cupcakes.

But the films work equally well with actual children who can't seem to ditch childish things fast enough. (Market researchers report that children who once identified themselves as children until the age of 12 are now advancing out of kiddie culture at 8 or 9.)

These groups increasingly meet, at least for two hours at a stretch, within the context of films like the 2004 summer hit "Shrek 2," which worked both as a broad comedy about a flatulent ogre and a parable about the trouble relating to in-laws, or "The Incredibles," which offered a midlife crisis story wrapped in a superhero adventure story.

"Superheroes are now part of our adult psyches," said Don Payne, the screenwriter of the comedy "My Super Ex-Girlfriend," a July release that attempts to marry the superhero genre with the romantic sensibility of late-70's Woody Allen. "All of us have grown up and held onto our childhoods, even as we've twisted them into new adult contexts."

All of which has turned the production of summer movies into maddening demographic exercise, as filmmakers chase an audience that is in the process of redefining itself. The most successful examples — "Pirates of the Caribbean," "Napoleon Dynamite" or the movie that basically invented the form, "Star Wars" — strike "an exceedingly delicate balance," Mr. Singer said. Veer too far into potty humor or frenetic action, and you bore the adults; linger too long in character development or broad themes, and you alienate the children.

To play across the age divide, some filmmakers adopt the strategy perfected by the creators of the classic Warner Brothers cartoons, packing their pictures with in-jokes and asides they know will hit home with grown-ups even if they mystify kids. "The 60's weren't good to you were they?" an Army jeep asks a spaced-out Volkswagen in a preview for Pixar's "Cars."

Others, however, reject that approach, like the director M. Night Shyamalan, who calls it "bifurcation." Instead of tossing out lines that appeal to either one group or another, he seeks to inject deeply adult themes into stories that otherwise seem of interest only to children. Thus Mr. Shyamalan's "Lady in the Water," set for release on July 21, and billed as "a bedtime story," is being positioned as a sort of romper-room version of the dark, supernatural thrillers he is famous for.

And while the movie is intended for children — it grew out of stories Mr. Shyamalan told his own kids — it's far deeper and more surreal than most such entertainment, he said. He admitted to worrying during production that it might be "too whacked or scary," but said he decided to follow the example of children's authors like J. M. Barrie and Roald Dahl, whose greatest works willfully ran afoul of rules of propriety and age appropriateness.

"To me it was all about getting back to pure rebellion and free-spiritedness of childhood," the 35-year-old Mr. Shyamalan said, in true "rejuvenile" fashion. "That's been incredibly freeing. Since I did this, I'm a completely different person."

In a similar vein "The Ant Bully," set for release by Warner Brothers in early August, features a cast of insects voiced by Julia Roberts, Nicolas Cage and Meryl Streep in what the film's writer and director, John A. Davis, said could be read as a parable about world affairs and the use and abuse of power. "I wanted this movie to echo our times," he said. "It's good to push certain moral buttons, and if you can do that in an exciting story with great visuals, so much the better."

However thrilling their creative possibilities, though, at root such hybrids owe their prevalence to industry economics. Studio executives are well aware that the difference between a successful children's movie and a successful children's movie that adults also enjoy is the difference between a hit and a bonafide blockbuster.

Movies like the first "Spider-Man" may have appealed to kids primarily, but according to Sony exit polls, 52 percent of the audience was over 25. More generally, the highest grossing films of the modern era — "Star Wars," "Shrek 2," "E.T. the Extra-Terrestrial" — is largely a catalog of kid-adult hybrids, notwithstanding the occasional success of a "Titanic" or "The Passion of the Christ" (or the decision by Sony Pictures this year to buck the trend by releasing "The Da Vinci Code" as a summer film).

"That's what everyone is really aiming for," said Bonnie Arnold, producer of the new DreamWorks feature "Over the Hedge," which mixes talking-animal high jinks with commentary on the politics of homeowner associations, the challenges of big-box shopping and lawn care. "These movies have got to please their core kid audience, but they're really successful when they branch out beyond kids."

Even if the result is a weird kind of Peter Pan movie that never lets its audience entirely grow up and never lets children be entirely young, more than a few parents prize the new hybrid film as a chance to connect with their children. The parents of the mid-20th century might have been content to let their kids enjoy Hopalong Cassidy or Howdy Doody on their own, but today's parents expect to join the fun. "There's nothing greater than being in the same theater as your kid and laughing at the same jokes," said Julia Pistor, mother of three and executive vice president of Nickelodeon Movies, which is releasing the Jack Black comedy "Nacho Libre."

But parents with higher expectations aren't the only adults driving the change; Mr. Blake said that about 25 percent of the audience for any hit family movie is now made up of adults unaccompanied by children. The producer Suzanne Todd recalls scanning the audience at a showing of the recent Disney remake of "The Shaggy Dog" and noticing how many were adults with nary a child in sight. "I can understand why," Ms. Todd said, especially in a "cynical age where we've lost our moral ballast. Adults need entertainment that's fun, easy and offers 90 minutes off from real life."

For his part Barry Sonnenfeld, director of the family-friendly road movie "RV," said the growing adult audience had shaken up previously stale genres, allowing for more complex characters and potentially objectionable material. "It allows you to make movies that aren't so down the middle," he said. The father portrayed by Robin Williams in "RV," for instance, is far more needy and self-involved than the typical Disney dad, while the movie's central set piece involves an explosive, 100-foot spout of fecal matter. ("And we still got our PG," Mr. Sonnenfeld said.)

Still, filmmakers agonize endlessly over the precise combination of kid and adult elements. Producers of "Over the Hedge" worried, for instance, about a character called Hammy, a hyperactive squirrel who, it was thought, might strike some adults as a too-vivid characterization of a toddler on a sugar rush. In screenings, however, the filmmakers were relieved to discover that Hammy tested well across the age spectrum. Ms. Hunt said, "You have to ask yourself: 'Is this playing too young? Are we getting too sophisticated or clever for our own good?' "

Mr. Payne said he learned how to strike the right balance while writing for "The Simpsons," the Fox series that has become a model mixture of broad-appeal comedy and transgressive adult humor. The trick, he said, is to bounce back quickly the moment you go to far in one direction. "When you find yourself on a run about socialism," he said, "you know that pretty quick you've got to light Homer's pants on fire."

Such divisions are increasingly irrelevant, however, since it's easier than ever to please younger and older moviegoers with exactly the same material, now that children are now more sophisticated and adults more childlike (and childish). It's now possible, Mr. Sonnenfeld said, to stay fixed on a sort of psychic middle ground.

"You can now make a movie for 20-year-olds, and teenagers will come because it makes them feel older, and adults will come because it makes them feel younger," Mr. Sonnenfeld said. "If you do it right, you catch everyone coming and going."

Christopher Noxon is the author of "Rejuvenile: Kickball, Cartoons, Cupcakes and the Reinvention of the American Grown-up," which is to be published on June 20 by Crown/Random House.

TOKYO

ALL cities takes a toll, and at times all city dwellers have to take their leave. When life in Istanbul gets too stressful, people can head to the baths. In Rio there's the beach. In Tokyo, though, the antidote to urban overload is more of the same. In the world's most media-saturated city, people take a break by checking themselves into media immersion pods: warrens cluttered with computers, TV's, video games and every other entertainment of the electronic age.

The Bagus Gran Cyber Cafés are Tokyo's grand temples of infomania. Situated well above retail level, on the odd floor number where in Manhattan you might find tarot readers or nail salons, these establishments contain row after row of anonymous cubicles. At first glance the spread looks officelike, but be warned: these places are drug dens for Internet addicts.

The first Gran Cyber Café opened in 1999. Today there are 10, serving some 5,000 people a day. Each has a slightly different orientation — some are geared to teenagers, some to salarymen — but the atmosphere is the same throughout the franchise: equal parts lending library, newsstand, arcade, Kinko's and youth hostel. An inspired extension of the basic Internet cafe, the Gran Cyber Cafés shift their meaning the more you study them, as if by a trick of their trademark low light.

Sometimes they look like nothing special, only marginally cooler than carrels you might find at a college library. But at other times, especially late at night, they seem visionary, an architectural realization of the social and personal life of the future.

"The Japanese love liminal spaces and gray zones," explained Con Isshow, a writer who has published widely on youth culture, including a collection of letters by abused children called "Letters to Japan's Worst Parents."

"In both the anonymity and role-playing games on offer at the Gran Cyber Café, you don't have to exist in tight social norms," Mr. Isshow told me. "Your identity can be in flux. You go to these places not to present yourself, but to lose yourself. Lose your name, your position, your pride."

Mr. Isshow spoke through a translator, but here he introduced some English: "No-face-man, no-ID-man, no-pride-man."

Although the services offered by Bagus, a company that also runs billiard halls, karaoke dens and spas, are aboveboard, the Gran Cyber Cafés are enshrouded in the urgent, furtive atmosphere of a hot-sheet motel. Eyes averted, customers sign in, head to the library of entertainment options, and load up on fashion magazines, video games and DVD's of "24" as if stocking up on Jim Beam. Then they beetle-brow it to their solitary pods.

What they do there is up to them. Some people channel-surf. Others trade stocks. You can download music, read novels, watch pornography, play video games, have sex, go to sleep.

According to Mr. Isshow, Japan's "petit iede," or little runaways, come for downtime, free lattes and smoothies, and, at some branches, showers. They use the places as trial separations from home — staying a few hours, overnight or a few days, long enough to scare their parents. (A "night pack" allows use of the pod from 11 p.m. to 8 a.m. for about $10; some places sell toothbrushes and underwear too.) Periodically the management will remind a customer that the cafe is not a hotel, but above all Bagus respects people's privacy.

ON a recent afternoon, at around 5:30, I visited the Gran Cyber Café in the Shinjuku neighborhood for the first time, to read e-mail and visit a news site or two. Checking in, I was assigned to pod 16-A.

I loved 16-A the instant I saw it. I closed the door, slipped into a low-slung leatherette seat and surveyed the all-you-can-eat tech feast, which includes VHS and DVD players, satellite and regular television on a Toshiba set, PlayStation 2, Lineage II and a Compaq computer loaded with software, all the relevant downloads and hyperspeedy Internet. In the nearby library were thousands of comic books, magazines and novels. On the desk was a menu of oddball snacks, like boiled egg curry and hot sandwich tuna.

The atmosphere is airless and hot, with a permanent cloud of cigarette smoke. Over all the effect is of a low-wattage, low-oxygen casino.

When I spoke to Japanese cultural critics about the Gran Cyber Cafés, most gave high-flown theoretical accounts of their appeal. But Takami Yasuda, a professor at the School of Informatics and Sciences at Nagoya University who writes about virtual reality, shrugged. "I do not know exactly why people, young guys in particular, love to stay in such a dark place," he said.

I don't know exactly why I stayed either. But 10 books, two DVD's, seven magazines, two newspapers and a video game later, I found that eight hours had elapsed.

On my second visit I brought Shizu Yuasa, a married 31-year-old Japanese friend who stays overnight at Gran Cyber Cafés whenever she wants time to herself.

Shizu, the director of 2DK, an arts and media production company, is an avid reader of the Japanese graphic novels known as manga. But because she can read one in about 15 minutes, she doesn't believe in buying them. So she heads to the Bagus shelves and picks out 20 or so.

Around 8 p.m. the place filled up with a reticent and largely male crowd of loners. One nameless man told me he comes on breaks from work, to read the sports news. Naomi Iwasaki, a 28-year-old manager of an Internet portal site, said he was there to read manga. Two boys with hair dyed strawberry blond companionably watched their screens: one was tuned to a cooking show, the other to Yahoo.

Back in the stacks I met Reiko Ishii, a 25-year-old student at Hosei University who lives with her parents in Tokyo. She had tea-colored hair, wore a horn-shaped amulet around her neck, and dressed in the clingy style of early Nicole Richie. She told me she comes to Bagus often, but I was the only other customer she had ever spoken to. There are so few places, she said, where a woman can go out alone, late at night, without having to be sociable. I asked if she'd ever spent the night.

"Sure," she said, looking unfazed. "My parents know I stay here, and it's fine with them." She retreated to her pod. I went to mine too, hit the button that changed the keyboard from Chinese characters to QWERTY, and answered some e-mail.

Shizu was catching up on manga. One was "The Monetary System of Osaka," a left-wing chronicle of graft and usury among the suits of Japan's second city. Another was "Inu," or "Dog," by Haruko Kashiwagi. It's considered clever, fairly high-toned and mainstream, which is surprising because, in part, it's about a woman who has sex with her dog.

The extensive manga library also includes pornography for every taste. But sex at the Gran Cyber Café is not just in the fiction. All around me, couples were making out. Some were watching sex videos. They seemed blasé. Still, in the cubicles that seat two, the walls are a little lower, and the seats don't have a massage option. Meanwhile other customers have taken a more professional approach. The Japanese Web site Tanteifile.com published an article about a freelance prostitute — a "delivery health" girl — who moved into a Gran Cyber Café after her workplace was raided.

Shizu and I got tea and calpis, a sweet, summery drink, and returned to our pod. I leafed through teenage fashion magazines while a Japanese movie about gay samurai, "Mayonaka no Yaji-san Kita-san," played. Shizu, in the meantime, checked out Mixi, the Japanese Friendster. Some people, I had been told, use the site to communicate with other customers who might be just a few pods away, to communicate without having to introduce themselves in person.

Finally an attractive 30-something couple, Kaori Karasawa and Naoya Ohada, settled in the pod across from us. "Will this article be on the Internet?" Ms. Karasawa asked me. "People at the office don't really know we're dating."

"But now they will," Mr. Ohada said, laughing.

He appeared eager to impress her; he held forth about manga, while she listened. They Googled subjects that came up in conversation, showing each other favorite sites, using the Internet as a kind of third party in their relationship: chaperon, entertainment, common ground. Over their pod the light at the Gran Cyber Café seemed not dim but soft, flattering, romantic.

CHECKING out wasn't going to be easy. I had come to appreciate the shared solitude the Gran Cyber Café provides, as well as the fast, infallible Internet connection.

Hidenori Kimura, a sociologist who writes about intercultural encounters, said he believes the Gran Cyber Cafés fulfill a deep and persistent cultural longing. The Japanese system of competition for education, career and social esteem, Dr. Kimura explained, forces young people to obsess over self-presentation, which costs them both fantasy and anonymity, the privileges of childhood. What Japanese young people want, in his view, are opportunities to be free of their social status.

"Traditionally," he explained, "tea ceremonies and festivals have been fulfilling this role of depriving people of their social status and thus help them become 'nobody.' Tea ceremonies deprived the feudal elites of their status and made them just a person enjoying tea ceremony and tea, while festivals among farmers offered an enclave of anarchy during the festivals where they were free of norms and rules of feudal eras."

The Gran Cyber Cafés now serve this purpose, he said. "Nobody cares what you do, which enables you to be absorbed in whatever fantasy you want to indulge in through Net surfing, Web games or manga. Yet you can satisfy your timid desire to belong." Staying in the Gran Cyber Cafés, he concluded, is now part of jibun-sagashi, or the search for the true self.

Nevertheless there's something a little shameful about spending a solo hour, or two, or seven, on a wanton media bender. It was in Japan that I first heard the word "infomania," a 2005 coinage by Hewlett-Packard, whose study last May showed that compulsive e-mailing and text-messaging do more damage to the I.Q. than regular marijuana use. But, as I read about the study in my pod, I came to doubt that such warnings would ever make people temper their infomaniac ways; maybe these are the I.Q.'s we're stuck with now.

And, really, what's so wrong with getting lost on the Internet; watching soccer or baseball on satellite television; devouring Us Weekly or Time Asia; and organizing solo marathons of Tim Burton or Kurosawa movies? The craving for media sprees runs deep, and, like so many Internet-era developments, Gran Cyber Cafés seem to answer an almost carnal need for uninterrupted access to pixels and screens and Web sites and instant-messaging and iTunes. And when that need is satisfied, you can always return to life in the city, at least for a while.

FAIRHOPE, Ala.

EVER since its founding in 1894 by a group of 28 utopian dreamers from Iowa, this quaint waterside town on the eastern shore of Mobile Bay has been a refuge for what Southerners politely call "characters."

There was Craig Sheldon, a sculptor known for making fantastical creatures, like a wacky insect he called "head holding high hopper," and Winifred Duncan, a spinster who lived by the water with four bloodhounds and was regularly arrested for canoeing at night in the bay, naked.

Strangest of all, perhaps, was an Idaho man named Henry Stuart, who moved to Fairhope in the 1920's, after being told by his doctor — incorrectly, it turned out — that he had only a year to live.

Mr. Stuart, who wore a long white beard and became known locally as the Hermit of Montrose, after a neighborhood in Fairhope, built himself a small round hurricane-proof hut out of concrete and lived in it for 18 years, apparently certain he might die at any moment. Mr. Stuart eventually died at 88 in 1946, somewhere in Oregon.

Today, Mr. Stuart's hut in Fairhope has become an odd sort of tourist attraction, a kind of temple to eccentricity and individualism, thanks largely to another Fairhope eccentric, a goateed man often seen in a seersucker suit riding around town on a Harley-Davidson: the novelist Sonny Brewer.

Since the publication last year of Mr. Brewer's first novel, "The Poet of Tolstoy Park" (Ballantine), which is based on Mr. Stuart's life and the construction of his concrete hut, readers, along with various searchers, spiritualists and philosophical types, have been turning up at the hut to commune with Mr. Stuart. Two thousand people have signed a guest book Mr. Brewer left in the hut last year, and some have brought sleeping bags and spent the night inside.

"It's a special place," said Jimbo Meador, 64, a kayak designer who lives in nearby Point Clear and who meditates regularly in the hut. "The acoustics in there are pretty unusual. Like you say, 'Om,' and it really resonates."

Mr. Brewer, who is 57, is quick to cop to the charge of being an oddball, even by Fairhope standards. He has been a carpenter, a bookstore owner, a real estate agent, an editor and a rock musician, and he once sold vintage cars for a living, though he lost money at it.

Mr. Brewer has also been through a boat phase, an R.V. phase, a convertible phase, and several motorcycle phases. As for religions, he's tried a bunch of those, too: He was raised a Baptist, became a Methodist, a Presbyterian, a Quaker, and converted to Catholicism for a while. Mr. Brewer said he's an Episcopalian — for now.

"I sometimes have a feeling I'm from another planet," Mr. Brewer said in a soft southern Alabama drawl. "Even my own behavior looks alien and ridiculous to me."

Mr. Brewer discovered Henry Stuart's hut in the 1980's during one of those career changes. He had quit his job as a carpenter, and was on his way to a seminar on selling real estate when he pulled into a parking lot about a mile from town. Though originally built on 10 acres of wilderness, the hut in the intervening years had been encroached upon as Fairhope grew. Office buildings have been built to within six feet of the dwelling. It now sits just off the parking lot of a local Coldwell Banker office, which used the hut for years to store its "for sale" signs.

"I thought, 'What is this crazy little house doing in a parking lot?' " Mr. Brewer recalled. "It was like finding a very strange bird nest in the forest. You want to know, 'What kind of bird built this?' "

Inside the real estate office, Mr. Brewer came across a framed copy of a newspaper article about Mr. Stuart and his hut. Mr. Stuart, the article said, left behind two grown sons in Idaho when he came South to die. He admired Tolstoy, naming the acreage around the hut Tolstoy Park, and with his white beard even resembled him.

Mr. Stuart was described as quick to lend a dollar, and unconcerned about repayment. And though described as a hermit, he accepted visitors regularly; 1,200 people signed a guest book he kept in his hut, according to one article, including the lawyer Clarence Darrow.

Mr. Stuart, who was in his late 60's at the time, built his hut over the course of a year and 16 days in 1925 and 1926, and refused all help with the construction, the newspaper reported. Mr. Stuart's bed was a hammock that hung 10 feet off the ground; he could get in only by climbing a ladder. He kept a loom on the floor that he used to weave rugs, which he sold for a living.

"I was completely mesmerized," Mr. Brewer said.

He managed to find two other newspaper articles about Mr. Stuart, and six photographs. Mr. Stuart is barefoot in all of them, even one taken with a woman in a winter coat.

The more Mr. Brewer learned about the man, he said, the more obsessed he became.

"I identified with Henry; he did what he wanted to do, and so did I," Mr. Brewer said.

He decided to try to write about Henry Stuart. He considered a nonfiction account of Mr. Stuart's life, but settled on fiction, "because I lie," he said. He wrote a couple of short stories about Mr. Stuart, and the first 20 pages of a novel, but put it aside in favor of an autobiographical novel about his own life, which he sent to a literary agent in San Francisco.

By now, Mr. Brewer had quit real estate to open an independent bookstore called Over the Transom, in Fairhope. It was losing money — a lot of money. Mr. Brewer's only hope was that his novel would sell, but his agent was not optimistic and asked him if he had anything else. Mr. Brewer mentioned the Stuart novel, which begins with Mr. Stuart taking off his shoes after hearing the news that he will die. Based on the first 20 pages and a six-page outline, the agent sold the novel to Ballantine for $100,000.

Mr. Brewer said he got the news hours before an appointment with a bankruptcy lawyer.

"I broke down and cried," he said.

Mr. Brewer's next move was to persuade a local banker who owns the hut and the land around it to rent the building to him for $9 a month. He wrote a draft of "The Poet of Tolstoy Park" in four fevered months, and then immediately set about restoring the hut, ridding it of "snakes and lizards and fast-food wrappers," he said, replacing windows and removing a wooden floor. When he was finished, he moved in to revise his novel — while barefoot.

"Where did Henry Stuart stop and Sonny Brewer start?" Mr. Brewer asked. "That line was not clear. Some ladies from the real estate office told me they thought I had gone crazy."

A local architect who studied the hut noticed that the diameter of the floor, 14 feet, perfectly matched the distance between the floor and the top of the hut's domed roof. The hut was also dug 16 inches into the ground, which at that depth is a constant 57 degrees, making the floor cool in the summer and warm in the winter.

When he was finished with his book, Mr. Brewer left a copy of the manuscript in the hut, and then left the door unlocked. Shortly after publication last year, he began to hear from people who had visited.

One of those people was Wilson McDuff, 35, a schoolteacher from Fairhope who spent a night in the hut last year with his father and son. "It was kind of weird to me," Mr. McDuff said. "I started imagining what it would be like to be Henry Stuart, living in a little bitty house like that. I was inspired."

Mr. McDuff's father died later that year in a cycling accident. Unable to sleep the night he heard the news, Mr. McDuff said he was drawn back to the hut. "I didn't feel like I was alone anymore," he said. "It was comforting to think about Henry Stuart and to know that just because you're not here doesn't mean you're forgotten."

Somewhere along the way, Mr. Brewer said, people began leaving coins and dollar bills in an iron skillet in the hut, money that seems to be lent and borrowed according to Mr. Stuart's principles.

"Sometimes I come in here and it's $65, sometimes it's $5," Mr. Brewer said with a shrug. "The pile just comes and goes."

Mr. Brewer said that so far he has remained on good terms with the banker who owns the hut. But one thought keeps him up at night.

"My fear is that sooner or later the proverbial offer that can't be refused might come along," he added. "I could see a Blockbuster Video standing where Henry's house is."

That thought has inspired Mr. Brewer's latest crusade: getting the hut placed on the National Register of Historic Places, a move that could help preserve it in perpetuity. So far it hasn't gone so well. Though the State of Alabama designated the hut a landmark, the United States Department of the Interior said that his application needed more work.

"They said it was too weird," Mr. Brewer said.

LONDON, May 10 — He had been shot at in Zambia, stung by bees in Gambia. There had been volcanoes, arrests and accidents. But when the round-the-world cyclist Heinz Stücke reached Britain, he suffered the cruelest cut of all: his bike was stolen.

It is a moot point whether the story made the headlines because of the loneliness of the long-distance biker, or as yet one more snippet of evidence that — even as politicians debate a wave of serious crime in Britain — a lesser tide of pilfering still washes the nation's shorelines.

Mr. Stücke has been pedaling, on and off — but always on the same bicycle — since 1962 when he left his home at Hövelhof in western Germany at the age of 22 rather than contemplate a lifetime as a tool and die maker.

Since then he has pedaled an estimated 335,000 miles across 211 countries and territories. In long-range cycling circles he is something of a celebrity, a kind of two-wheeled Forrest Gump who never decided he had said all he had to say about cycling. His nom de pedal is "the Bike Man."

Between 1995 and 1999 the Guinness Book of Records listed Mr. Stücke as the world's most traveled man.

In recent years, though, he has been obliged to look for ever more remote places to visit as he has filled his wish list of visits to sovereign states and their dependencies. So he decided to head from Le Havre, France, to Greenland, via Britain.

Last Monday he landed in Portsmouth, southern England, pitched his tent, and covered his ancient bicycle with string, canvas and bungee chords, tethering it outside the tent flap.

"I even left my door open so that I could see it, but when I awoke at 3 a.m., it had gone," The Times of London quoted him as saying.

In these days of multispeed, titanium-framed, shock-absorbed mountain bikes, it was no ordinary bicycle. It had a modest three speeds and a hub brake. It weighed 56 pounds because its frame had been reinforced against fractures, and its spokes had been thickened to cope with the rugged terrain, according to a Web posting by Mr. Stücke (http://bikechina.com/ct-heinzstucke1z.html).

It had an extra set of handlebars so Mr. Stücke could modify his riding position to ease shoulder pain. It had crossed the Syrian desert to set a personal record of about 200 miles in 12 hours "with the help of strong tailwinds." It had been to high altitudes in India and Tibet, across Afghanistan (in 1978) and above the snow line in the mountainous African kingdom of Lesotho, not to mention below street level in the rutted tracks of less elevated Africa.

Friends and supporters had donated cash to keep him going. Even Haile Selassie, the emperor of Ethiopia who died in 1975 — "whom I had the honor to meet" — was listed as a donor of $500.

"All that matters to me is traveling on my bike," Mr. Stücke, 66, told the BBC. "That bike has sentimental value. In the past I have cycled up to 100 kilometers a day on it." That's about 62 miles.

The police were concerned at the bike's disappearance. Constable Paul Jones even went through the police lost-property store and found a bike to lend him. But Mr. Stücke never abandoned hope that his trusty two-wheeler would be returned.

"I expected it to be found, because it's not a flashy one, it's not an expensive one," he said.

And it was.

An unidentified person found it abandoned in a park. And it was handed back to him, to his relief.

"Hallelujah, praise the Lord — I have got my beautiful bike back," Mr. Stücke told reporters. "Is there any other bike like this in the world? It's the one thing I have to have for my life and my livelihood. Now I can rejoice and my journey can continue."

"All that matters to me is traveling on my bike, that's all I ever wanted to do," he said. "I will be locking it up for at least the next few years. Perhaps I will attach a piece of string to my toe connected to the bike while I sleep."

It was not, though, the first — or the most in-your-face — crime that Mr. Stücke faced in his travels. That doubtful honor, according to the Web posting, went to an unidentified trickster who offered Mr. Stücke a lift near New York as he struggled to return to Costa Rica, where he had left his bicycle for safe-keeping.

"Not far from New York, a man picked me up," Mr. Stücke said. "After some time he stopped in front of a drug store in a shopping center, gave me 30 cents and said: 'Would you be so kind as to jump out and get me two cigars, Dutch Master Blond?' I said: 'Sure.' By the time I came out he had driven away with all my belongings in the car — camera, 1,000 selected slides, passport, my diary, equipment, everything."

His Web posting continued: "At such a time I remembered my motto: Every blow that does not kill me only makes me stronger."

Priests vow to remain celibate, physicians vow to do no harm, and letter carriers vow to swiftly complete their appointed rounds despite snow, sleet, and split infinitives. Few people realize that psychologists also take a vow, promising that at some point in their professional lives they will publish a book, a chapter, or at least an article that contains this sentence: "The human being is the only animal that ..." We are allowed to finish the sentence any way we like, of course, but it has to start with those eight words. Most of us wait until relatively late in our careers to fulfill this solemn obligation because we know that successive generations of psychologists will ignore all the other words that we managed to pack into a lifetime of well-intentioned scholarship and remember us mainly for how we finished The Sentence. We also know that the worse we do, the better we will be remembered. For instance, those psychologists who finished The Sentence with "can use language" were particularly well remembered when chimpanzees were taught to communicate with hand signs. And when researchers discovered that chimps in the wild use sticks to extract tasty termites from their mounds (and to bash one another over the head now and then), the world suddenly remembered the full name and mailing address of every psychologist who had ever finished The Sentence with "uses tools." So it is for good reason that most psychologists put off completing The Sentence for as long as they can, hoping that if they wait long enough, they just might die in time to avoid being publicly humiliated by a monkey.

I have never before written The Sentence, but I'd like to do so now, with you as my witness. The human being is the only animal that thinks about the future. Now, let me say up front that I've had cats, I've had dogs, I've had gerbils, mice, goldfish, and crabs (no, not that kind), and I do recognize that nonhuman animals often act as though they have the capacity to think about the future. But as bald men with cheap hairpieces always seem to forget, acting as though you have something and actually having it are not the same thing, and anyone who looks closely can tell the difference. For example, I live in an urban neighborhood, and every autumn the squirrels in my yard (which is approximately the size of two squirrels) act as though they know that they will be unable to eat later unless they bury some food now. My city has a relatively well-educated citizenry, but as far as anyone can tell its squirrels are not particularly distinguished. Rather, they have regular squirrel brains that run food-burying programs when the amount of sun- light that enters their regular squirrel eyes decreases by a critical amount. Shortened days trigger burying behavior with no intervening contemplation of tomorrow, and the squirrel that stashes a nut in my yard "knows" about the future in approximately the same way that a falling rock "knows" about the law of gravity-which is to say, not really. Until a chimp weeps at the thought of growing old alone, or smiles as it contemplates its summer vacation, or turns down a taffy apple because it already looks too fat in shorts, I will stand by my version of The Sentence. We think about the future in a way that no other animal can, does, or ever has, and this simple, ubiquitous, ordinary act is a defining feature of our humanity.

The Joy of Next

If you were asked to name the human brain's greatest achievement, you might think first of the impressive artifacts it has produced-the Great Pyramid of Giza, the International Space Station, or perhaps the Golden Gate Bridge. These are great achievements indeed, and our brains deserve their very own ticker-tape parade for producing them. But they are not the greatest. A sophisticated machine could design and build any one of these things because designing and building require knowledge, logic, and patience, of which sophisticated machines have plenty. In fact, there's really only one achievement so remarkable that even the most sophisticated machine cannot pretend to have accomplished it, and that achievement is conscious experience. Seeing the Great Pyramid or remembering the Golden Gate or imagining the Space Station are far more remarkable acts than is building any one of them. What's more, one of these remarkable acts is even more remarkable than the others. To see is to experience the world as it is, to remember is to experience the world as it was, but to imagine-ah, to imagine is to experience the world as it isn't and has never been, but as it might be. The greatest achievement of the human brain is its ability to imagine objects and episodes that do not exist in the realm of the real, and it is this ability that allows us to think about the future. As one philosopher noted, the human brain is an "anticipation machine," and "making future" is the most important thing it does.

But what exactly does "making future" mean? There are at least two ways in which brains might be said to make future, one of which we share with many other animals, the other of which we share with none. All brains-human brains, chimpanzee brains, even regular food-burying squirrel brains-make predictions about the immediate, local, personal, future. They do this by using information about current events ("I smell something") and past events ("Last time I smelled this smell, a big thing tried to eat me") to anticipate the event that is most likely to happen to them next ("A big thing is about to --"). ut notice two features of this so-called prediction. First, despite the comic quips inside the parentheses, predictions such as these do not require the brain making them to have anything even remotely resembling a conscious thought. Just as an abacus can put two and two together to produce four without having thoughts about arithmetic, so brains can add past to present to make future without ever thinking about any of them. In fact, it doesn't even require a brain to make predictions such as these. With just a little bit of training, the giant sea slug known as Aplysia parvula can learn to predict and avoid an electric shock to its gill, and as anyone with a scalpel can easily demonstrate, sea slugs are inarguably brainless. Computers are also brainless, but they use precisely the same trick the sea slug does when they turn down your credit card because you were trying to buy dinner in Paris after buying lunch in Hoboken. In short, machines and invertebrates prove that it doesn't take a smart, self-aware, conscious, brain to make simple predictions about the future.

The second thing to notice is that predictions such as these are not particularly far-reaching. They are not predictions in the same sense that we might predict the annual rate of inflation, the intellectual impact of postmodernism, the heat death of the universe, or Madonna's next hair color. Rather, these are predictions about what will happen in precisely this spot, precisely next, to precisely me, and we call them predictions only because there is no better word for them in the English language. But the use of that term-with its inescapable connotations of calculated, thoughtful reflection about events that may occur anywhere, to anyone, at any time-risks obscuring the fact that brains are continuously making predictions about the immediate, local, personal, future of their owners without their owners' awareness. Rather than saying that such brains are predicting, let's say that they are nexting.

Yours is nexting right now. For example, at this moment you may be consciously thinking about the sentence you just read, or about the key ring in your pocket that is jammed uncomfortably against your thigh, or about whether the War of 1812 really deserves its own overture. Whatever you are thinking, your thoughts are surely about something other than the word with which this sentence will end. But even as you hear these very words echoing in your very head, and think whatever thoughts they inspire, your brain is using the word it is reading right now and the words it read just before to make a reasonable guess about the identity of the word it will read next, which is what allows you to read so fluently. Any brain that has been raised on a steady diet of film noir and cheap detective novels fully expects the word night to follow the phrase It was a dark and stormy, and thus when it does encounter the word night, it is especially well prepared to digest it. As long as your brain's guess about the next word turns out to be right, you cruise along happily, left to right, left to right, turning black squiggles into ideas, scenes, characters, and concepts, blissfully unaware that your nexting brain is predicting the future of the sentence at a fantastic rate. It is only when your brain predicts badly that you suddenly feel avocado.

That is, surprised. See?

Now, consider the meaning of that brief moment of surprise. Surprise is an emotion we feel when we encounter the unexpected-for example, thirty-four acquaintances in paper hats standing in our living room yelling "Happy birthday!" as we walk through the front door with a bag of groceries and a full bladder-and thus the occurrence of surprise reveals the nature of our expectations. The surprise you felt at the end of the last paragraph reveals that as you were reading the phrase it is only when your brain predicts badly that you suddenly feel ..., your brain was simultaneously making a reasonable prediction about what would happen next. It predicted that sometime in the next few milliseconds your eyes would come across a set of black squiggles that encoded an English word that described a feeling, such as sad or nauseous or even surprised. Instead, it encountered a fruit, which woke you from your dogmatic slumbers and revealed the nature of your expectations to anyone who was watching. Surprise tells us that we were expecting something other than what we got, even when we didn't know we were expecting anything at all.

Because feelings of surprise are generally accompanied by reactions that can be observed and measured-such as eyebrow arching, eye widening, jaw dropping, and noises followed by a series of exclamation marks-psychologists can use surprise to tell them when a brain is nexting. For example, when monkeys see a researcher drop a ball down one of several chutes, they quickly look to the bottom of that chute and wait for the ball to reemerge. When some experimental trickery causes the ball to emerge from a different chute than the one in which it was deposited, the monkeys display surprise, presumably because their brains were nexting. Human babies have similar responses to weird physics. For example, when babies are shown a video of a big red block smashing into a little yellow block, they react with indifference when the little yellow block instantly goes careening off the screen. But when the little yellow block hesitates for just a moment or two before careening away, babies stare like bystanders at a train wreck-as though the delayed careening had violated some prediction made by their nexting brains. Studies such as these tell us that monkey brains "know" about gravity (objects fall down, not sideways) and that baby human brains "know" about kinetics (moving objects transfer energy to stationary objects at precisely the moment they contact them and not a few seconds later). But more important, they tell us that monkey brains and baby human brains add what they already know (the past) to what they currently see (the present) to predict what will happen next (the future). When the actual next thing is different from the predicted next thing, monkeys and babies experience surprise.

Our brains were made for nexting, and that's just what they'll do. When we take a stroll on the beach, our brains predict how stable the sand will be when our foot hits it, and then adjust the tension in our knee accordingly. When we leap to catch a Frisbee, our brains predict where the disc will be when we cross its flight path, and then bring our hands to precisely that point. When we see a sand crab scurry behind a bit of driftwood on its way to the water, our brains predict when and where the critter will reappear, and then direct our eyes to the precise point of its reemergence. These predictions are remarkable in both the speed and accuracy with which they are made, and it is difficult to imagine what our lives would be like if our brains quit making them, leaving us completely "in the moment" and unable to take our next step. But while these automatic, continuous, nonconscious predictions of the immediate, local, personal, future are both amazing and ubiquitous, they are not the sorts of predictions that got our species out of the trees and into dress slacks. In fact, these are the kinds of predictions that frogs make without ever leaving their lily pads, and hence not the sort that The Sentence was meant to describe. No, the variety of future that we human beings manufacture-and that only we manufacture-is of another sort entirely. . . .

What would have happened if, at the end of "Casablanca," Ingrid Bergman had stayed with Humphrey Bogart in Morocco, rather than boarding the plane to Lisbon with her Nazi-fighting husband? Would she have regretted it? Or did she end up lamenting the decision she did make? According to Daniel Gilbert, odds are that either decision would have made her equally happy in the long run.

If this sounds like an odd question for a professor of psychology at Harvard to ask in a serious book about cognitive science, there are dozens more where that came from. Is it really possible that Christopher Reeve believed himself in some ways better off after he became a quadriplegic, or that Lance Armstrong is glad to have had cancer, or that cancer patients in general tend to be more optimistic about the future than healthy people? (Answers: yes, yes and yes.)

Which raises another question: If people who we think should be unhappy are not, is it also possible that some people are happy and don't know it? (Clinically speaking, yes. There is a syndrome called alexithymia in which a person experiences the same physiological response associated with an emotion as a normal person, as recorded by an M.R.I. scan, but is unaware of having the emotion.)

Gilbert is an influential researcher in happiness studies, an interdisciplinary field that has attracted psychologists, economists and other empirically minded researchers, not to mention a lot of interested students. (As The Boston Globe recently reported, a course on "positive psychology" taught by one of Gilbert's colleagues is the most popular course at Harvard.) But from the acknowledgments page forward, it's clear Gilbert also fancies himself a comedian. Uh-oh, cringe alert: an academic who cracks wise. But Gilbert's elbow-in-the-ribs social-science humor is actually funny, at least some of the time. "When we have an experience . . . on successive occasions, we quickly begin to adapt to it, and the experience yields less pleasure each time," he writes. "Psychologists calls this habituation, economists call it declining marginal utility, and the rest of us call it marriage."

But underneath the goofball brilliance, Gilbert has a serious argument to make about why human beings are forever wrongly predicting what will make them happy. Because of logic-processing errors our brains tend to make, we don't want the things that would make us happy — and the things that we want (more money, say, or a bigger house or a fancier car) won't make us happy.

Happiness is a subjective emotional state, so when you and I say that we are "extremely happy" we may mean completely different things. Most people would find the idea of being a conjoined twin to be a horrible fate. You couldn't possibly be happy in that condition, right? Then how come conjoined twins rate themselves as happy as nonconjoined people, Gilbert asks. Is that because they don't know what "real" happiness is? Or are you wrong to think that you couldn't be happy as a conjoined twin?

Not knowing what makes other people happy is one thing. But shouldn't we be able to figure out what will make ourselves happy? No, Gilbert argues, for the same reasons we can't imagine accurately how happy we would be as a conjoined twin. For one thing, we change across time; the person you are when you are imagining what it would be like to have that fancy new car is not the person you will be when you actually have that fancy new car.

"Teenagers get tattoos because they are confident that DEATH ROCKS will always be an appealing motto," he writes. "Smokers who have just finished a cigarette are confident for at least five minutes that they can quit and that their resolve will not diminish with the nicotine in their bloodstreams." For another, as Gilbert shows through a series of logic games and diagrams meant to dupe the reader (they worked on me), we misperceive reality — as philosophers since Kant have recognized — and then use those misperceptions to build a mistaken view of the future.

Events that we anticipate will give us joy make us less happy than we think; things that fill us with dread will make us less unhappy, for less long, than we anticipate. As evidence, Gilbert cites studies showing that a large majority of people who endure major trauma (wars, car accidents, rapes) in their lives will return successfully to their pre-trauma emotional state — and that many of them will report that they ended up happier than they were before the trauma. It's as though we're equipped with a hedonic thermostat that is constantly resetting us back to our emotional baseline.

The book is studded with research supporting this notion: Gore voters in the drawn-out 2000 election who wrongly predicted how unhappy they would be, and for how long, if Bush were declared the victor; college students who mistakenly predict how miserable they would feel if their football team lost; and people who overestimated how long they'd feel blue over a lost love or a lost job.

We even "mispredict" how things that we have already experienced will feel when they happen again. The classic example here is childbirth, which women seem to misremember as not being all that bad. We "expect the next car, the next house or the next promotion to make us happy even though the last ones didn't and even though others keep telling us that the next ones won't."

Gilbert argues that what he calls the "psychological immune system" kicks into gear in response to big negative events (the death of a spouse, the loss of a job) but not in response to small negative events (your car breaking down). Which means that our day-to-day happiness may be predicated more strongly on little events than on big ones. On its face, this sounds preposterous, but Gilbert cites study after study suggesting that it's true.

In an important sense, "Stumbling on Happiness" is a paean to delusion. "How do we manage to think of ourselves as great drivers, talented lovers and brilliant chefs when the facts of our lives include a pathetic parade of dented cars, disappointed partners and deflated soufflés?" Gilbert asks. "The answer is simple: We cook the facts."

At least since Freud, one of the abiding strains in psychological thought has been the idea that our behavior is often motivated by impulses beyond conscious awareness. Gilbert's argument is the cognitive scientist's version of Freudian delusion, with faulty logic — rather than the hidden longings of the unconscious — causing us to misperceive reality, and make decisions that are not in our rational, happiness-maximizing interest. What gets us through life, evidently, is just the right amount of delusion — enough to fool us into feeling relatively good about ourselves (as in Lake Wobegon, we all believe ourselves to be above average; 90 percent of drivers certainly do), but not so much as to exceed our own credulity. "If we were to experience the world exactly as it is, we'd be too depressed to get out of bed in the morning," Gilbert writes. "But if we were to experience the world exactly as we want it to be, we'd be too deluded to find our slippers."

Can awareness of these cognitive mechanisms make us happier, or at least less deluded? Alas, not really. In fact, that's sort of Gilbert's point: imagination (or projecting ourselves into the future) ought to be the key to predicting what will make us happy, but we're incapable of imagining accurately.

Interestingly, the clinically depressed seem less susceptible to these basic cognitive errors. For instance, healthy people can be deluded into greater happiness when granted the mere illusion of control over their environment; the clinically depressed recognize the illusion for what it is. All in all, it's yet more evidence that unhappy people have the more accurate view of reality — and that learning how to kid ourselves may be a key to mental health.

Scott Stossel is managing editor of The Atlantic Monthly.