Today, Langer’s studies are required reading in introductory psychology courses, and her work has inspired a generation of leading behavioral researchers who are rethinking human thought itself. But Langer herself has taken a different tack. As her intellectual successors publish research studies, she has transformed herself into almost an advertisement for her own work, setting out to spread the word about the power of mindfulness. Nearly a decade ago, she took up painting, pursuing it, as she pursues everything, as mindfully as possible; today her canvases, many of them whimsical portraits of her pet dogs, show in well-reputed galleries and sell for thousands of dollars. She has long been at work on a book on mindfulness and tennis, a sport she plays avidly. And her recent books are concerned less with how mindfulness works than how we all might better use it to improve our lives.

experiments that expose the strange power of the mind to fool itself and to transform the body. In one of her best-known studies, she found that giving nursing home residents more control over their lives made them live longer. In more recent work, she made hotel maids lose weight simply by telling them that their work burned as many calories as a typical workout. And in the study at the center of the Aniston movie, a team led by Langer found that instructing a group of elderly men to talk and act as if they were 20 years younger could reverse the aging process.

While other researchers might blanch at the Hollywoodization of their work, for Langer it’s almost an organic development - part of a long journey to bring the message of her research to the masses. Langer’s reputation in the field of social psychology rests on a set of ingenious

Langer is a famous psychologist poised to get much more famous, but not in the ways most researchers do. She is best known for two things: her concept of mindlessness - the idea that much of what we believe to be rational thought is in fact just our brains on autopilot - and her concept of mindfulness, the idea that simply paying attention to our everyday lives can make us happier and healthier. She was Harvard’s first tenured woman professor of psychology, and her discoveries helped trigger, among other things, the burgeoning positive-psychology movement. Her 1989 book, “Mindfulness,” was an international bestseller, and she remains in high demand as a speaker everywhere from New York’s 92d Street Y to the leadership guru Tony Robbins’s Fiji resort. And now a movie about her life is in development with Jennifer Aniston signed on to star as Langer.

STOCKBRIDGE - The Kripalu Center for Yoga and Health is housed in a former Jesuit seminary built in the 1950s, on a rise with broad views of the Berkshires. The long hallways have the institutional feel of a high school, except that everyone is speaking in respectful tones, and rolled yoga mats are everywhere, like baguettes in Doisneau’s Paris. On the walls are limited-edition photographs of lean people doing yoga in front of moss-dappled Indian shrines. At the gift shop on an early February weekend, visitors could have their tarot read, or a photographic portrait taken of their aura. And one of the featured speakers, offering a weekend-long seminar, was a senior professor at Harvard University, Ellen Langer.

At the time, the dominant view in the field of psychology assumed that human decision-making was a thoroughly logical process, driven by a constant calculation of probabilities and costs and benefits. The reaction to that botched deal made Langer suspect something very different.

As Langer sees it, it’s the pervasiveness of mindless behavior that makes mindfulness so powerful, and her earliest research focused on the former. Her doctoral dissertation, at Yale, grew out of a poker game with some colleagues. One round, the dealer accidentally skipped someone. “Everyone went crazy,” Langer recalls. It was out of the question, she learned, to simply give the skipped person the next card and proceed with the deal. She began to wonder why people were so attached to “their” cards even when they had no idea whether they were good or bad.

As advice, it was not revolutionary. But as the morning went on, and Langer described the research on which she had built her particular worldview, a sense emerged of just how powerful she thought the mind could be.

In responding to each, Langer returned to a similar point: Each of these complaints was born of mindlessness. They were instinctual responses rather than thoughtful engagement. Why not see the time alone at breakfast as a gift? Would the young mother rather have a child who blindly followed orders? And surely there was something interesting and redeemable to be found in the in-laws.

The night before, Langer had asked participants to think of someone or something that bothered them. She started the morning by asking what they had come up with. One woman said her husband was always late for breakfast, another described her child’s “defying” behavior, another made what sounded like a veiled complaint about her in-laws.

“I don’t think I’ve ever envied anybody. If someone has something, I can, too,” Langer announced to her Kripalu seminar during the Saturday morning session. Dressed in slim black slacks and a black, tunic-like cardigan, she stood before 65 people, mostly women, in a lofty, barn-shaped room that had once been the seminary’s main chapel.

“I do research, but my research is not designed to be a description. It rarely says what is, but what can be,” she told me at Kripalu.

For some psychologists, mantras like these make Langer less a social scientist than a guru. She treats research and writing - the day-to-day work of most psychologists - with a pronounced cavalierness, neglecting to publish results even when they strike her as interesting. At times she sounds suspicious of the very idea of scientific evidence. What she is practicing, she says, is a different brand of psychology, “the psychology of possibility.”

“Things are not good or bad,” she repeated to her audience at Kripalu, “What’s good or bad are the views we take of things.”

To test this, she ran a study in which she set up a lottery and varied the terms by which people got their tickets. She found that subjects valued their tickets much more when they were allowed to choose them, even though that did nothing to increase their chances of winning. She called this “the illusion of control.”

Langer followed this up by looking at the often meaningless factors that determine how people evaluate information. In one study, conducted with Benzion Chanowitz and Arthur Blank, she had experimenters approach people who were using a Xerox machine and ask to cut in to make copies. They found that people were more likely to let someone cut if offered a reason - but, intriguingly, it did not matter if the reason made sense. People were as receptive to a meaningless reason (“to make copies”) as a valid one (“I’m in a rush”).

“It is not that people don’t hear the request,” Langer wrote in “Mindfulness,” “they simply don’t think about it actively.”

These findings broke open the field of social psychology. “It was a huge corrective,” says John Bargh, a psychologist at Yale known for his work on “automaticity” and thought. He remembers reading the Xerox machine study as a graduate student: “That just lit me up. It opened my eyes and everything was off to the races after that.”

For Bargh and others, Langer’s research cleared the way for a whole new model of how people really think and decide, one that replaced the cold inner logician with a rich tangle that incorporated emotion, evolution, and the particularities of the human body. Researchers like Daniel Gilbert, Antonio Damasio, and Dan Ariely saw mindless behavior as a trove of clues, and in many cases, psychologists discovered that there could be a value to “mindlessness” - our seemingly irrational instincts were not only quicker, but often more accurate than our more considered ruminations.

Langer, on the other hand, thought mindlessness was harmful. Not paying attention to their lives, as she saw it, made people bored and careless, prejudiced and complacent; it stunted innovation and led to catastrophic errors among pilots and soldiers and surgeons. She didn’t see mindlessness as a window into the brain. She saw it as a condition to be cured.

So Langer began to study its opposite. She called it “mindfulness,” a term that was being independently adopted around the same time by doctors and therapists embracing the Buddhist practice of mindful meditation. Langer’s definition was something more everyday - that we simply need to go through life paying better attention to it. She began to focus her work on the question of what difference that might make.