brdgt | Science Tuesday - The Cute Factor, NOLA, Archaeology, Gentically modified plants and home remedies

The Cute Factor
By NATALIE ANGIER, The New York Times. January 3, 2006

WASHINGTON, Jan. 2 - If the mere sight of Tai Shan, the roly-poly, goofily gamboling masked bandit of a panda cub now on view at the National Zoo isn't enough to make you melt, then maybe the crush of his human onlookers, the furious flashing of their cameras and the heated gasps of their mass rapture will do the trick.

"Omigosh, look at him! He is too cute!"

"How adorable! I wish I could just reach in there and give him a big squeeze!"

"He's so fuzzy! I've never seen anything so cute in my life!"

A guard's sonorous voice rises above the burble. "OK, folks, five oohs and aahs per person, then it's time to let someone else step up front."

The 6-month-old, 25-pound Tai Shan - whose name is pronounced tie-SHON and means, for no obvious reason, "peaceful mountain" - is the first surviving giant panda cub ever born at the Smithsonian's zoo. And though the zoo's adult pandas have long been among Washington's top tourist attractions, the public debut of the baby in December has unleashed an almost bestial frenzy here. Some 13,000 timed tickets to see the cub were snapped up within two hours of being released, and almost immediately began trading on eBay for up to $200 a pair.

Panda mania is not the only reason that 2005 proved an exceptionally cute year. Last summer, a movie about another black-and-white charmer, the emperor penguin, became one of the highest-grossing documentaries of all time. Sales of petite, willfully cute cars like the Toyota Prius and the Mini Cooper soared, while those of noncute sport utility vehicles tanked.

Women's fashions opted for the cute over the sensible or glamorous, with low-slung slacks and skirts and abbreviated blouses contriving to present a customer's midriff as an adorable preschool bulge. Even the too big could be too cute. King Kong's newly reissued face has a squashed baby-doll appeal, and his passion for Naomi Watts ultimately feels like a serious case of puppy love - hopeless, heartbreaking, cute.

Scientists who study the evolution of visual signaling have identified a wide and still expanding assortment of features and behaviors that make something look cute: bright forward-facing eyes set low on a big round face, a pair of big round ears, floppy limbs and a side-to-side, teeter-totter gait, among many others.

Cute cues are those that indicate extreme youth, vulnerability, harmlessness and need, scientists say, and attending to them closely makes good Darwinian sense. As a species whose youngest members are so pathetically helpless they can't lift their heads to suckle without adult supervision, human beings must be wired to respond quickly and gamely to any and all signs of infantile desire.

The human cuteness detector is set at such a low bar, researchers said, that it sweeps in and deems cute practically anything remotely resembling a human baby or a part thereof, and so ends up including the young of virtually every mammalian species, fuzzy-headed birds like Japanese cranes, woolly bear caterpillars, a bobbing balloon, a big round rock stacked on a smaller rock, a colon, a hyphen and a close parenthesis typed in succession.

The greater the number of cute cues that an animal or object happens to possess, or the more exaggerated the signals may be, the louder and more italicized are the squeals provoked.

Cuteness is distinct from beauty, researchers say, emphasizing rounded over sculptured, soft over refined, clumsy over quick. Beauty attracts admiration and demands a pedestal; cuteness attracts affection and demands a lap. Beauty is rare and brutal, despoiled by a single pimple. Cuteness is commonplace and generous, content on occasion to cosegregate with homeliness.

Observing that many Floridians have an enormous affection for the manatee, which looks like an overfertilized potato with a sock puppet's face, Roger L. Reep of the University of Florida said it shone by grace of contrast. "People live hectic lives, and they may be feeling overwhelmed, but then they watch this soft and slow-moving animal, this gentle giant, and they see it turn on its back to get its belly scratched," said Dr. Reep, author with Robert K. Bonde of "The Florida Manatee: Biology and Conservation."

"That's very endearing," said Dr. Reep. "So even though a manatee is 3 times your size and 20 times your weight, you want to get into the water beside it."

Even as they say a cute tooth has rational roots, scientists admit they are just beginning to map its subtleties and source. New studies suggest that cute images stimulate the same pleasure centers of the brain aroused by sex, a good meal or psychoactive drugs like cocaine, which could explain why everybody in the panda house wore a big grin.

At the same time, said Denis Dutton, a philosopher of art at the University of Canterbury in New Zealand, the rapidity and promiscuity of the cute response makes the impulse suspect, readily overridden by the angry sense that one is being exploited or deceived.

"Cute cuts through all layers of meaning and says, Let's not worry about complexities, just love me," said Dr. Dutton, who is writing a book about Darwinian aesthetics. "That's where the sense of cheapness can come from, and the feeling of being manipulated or taken for a sucker that leads many to reject cuteness as low or shallow."

Quick and cheap make cute appealing to those who want to catch the eye and please the crowd. Advertisers and product designers are forever toying with cute cues to lend their merchandise instant appeal, mixing and monkeying with the vocabulary of cute to keep the message fresh and fetching.

That market-driven exercise in cultural evolution can yield bizarre if endearing results, like the blatantly ugly Cabbage Patch dolls, Furbies, the figgy face of E.T., the froggy one of Yoda. As though the original Volkswagen Beetle wasn't considered cute enough, the updated edition was made rounder and shinier still.

"The new Beetle looks like a smiley face," said Miles Orvell, professor of American studies at Temple University in Philadelphia. "By this point its origins in Hitler's regime, and its intended resemblance to a German helmet, is totally forgotten."

Whatever needs pitching, cute can help. A recent study at the Veterans Affairs Medical Center at the University of Michigan showed that high school students were far more likely to believe antismoking messages accompanied by cute cartoon characters like a penguin in a red jacket or a smirking polar bear than when the warnings were delivered unadorned.

"It made a huge difference," said Sonia A. Duffy, the lead author of the report, which was published in The Archives of Pediatrics and Adolescent Medicine. "The kids expressed more confidence in the cartoons than in the warnings themselves."

Primal and widespread though the taste for cute may be, researchers say it varies in strength and significance across cultures and eras. They compare the cute response to the love of sugar: everybody has sweetness receptors on the tongue, but some people, and some countries, eat a lot more candy than others.

Experts point out that the cuteness craze is particularly acute in Japan, where it goes by the name "kawaii" and has infiltrated the most masculine of redoubts. Truck drivers display Hello Kitty-style figurines on their dashboards. The police enliven safety billboards and wanted posters with two perky mouselike mascots, Pipo kun and Pipo chan.

Behind the kawaii phenomenon, according to Brian J. McVeigh, a scholar of East Asian studies at the University of Arizona, is the strongly hierarchical nature of Japanese culture. "Cuteness is used to soften up the vertical society," he said, "to soften power relations and present authority without being threatening."

In this country, the use of cute imagery is geared less toward blurring the line of command than toward celebrating America's favorite demographic: the young. Dr. Orvell traces contemporary cute chic to the 1960's, with its celebration of a perennial childhood, a refusal to dress in adult clothes, an inversion of adult values, a love of bright colors and bloopy, cartoony patterns, the Lava Lamp.

Today, it's not enough for a company to use cute graphics in its advertisements. It must have a really cute name as well. "Companies like Google and Yahoo leave no question in your mind about the youthfulness of their founders," said Dr. Orvell.

Madison Avenue may adapt its strategies for maximal tweaking of our inherent baby radar, but babies themselves, evolutionary scientists say, did not really evolve to be cute. Instead, most of their salient qualities stem from the demands of human anatomy and the human brain, and became appealing to a potential caretaker's eye only because infants wouldn't survive otherwise.

Human babies have unusually large heads because humans have unusually large brains. Their heads are round because their brains continue to grow throughout the first months of life, and the plates of the skull stay flexible and unfused to accommodate the development. Baby eyes and ears are situated comparatively far down the face and skull, and only later migrate upward in proportion to the development of bones in the cheek and jaw areas.

Baby eyes are also notably forward-facing, the binocular vision a likely legacy of our tree-dwelling ancestry, and all our favorite Disney characters also sport forward-facing eyes, including the ducks and mice, species that in reality have eyes on the sides of their heads.

The cartilage tissue in an infant's nose is comparatively soft and undeveloped, which is why most babies have button noses. Baby skin sits relatively loose on the body, rather than being taut, the better to stretch for growth spurts to come, said Paul H. Morris, an evolutionary scientist at the University of Portsmouth in England; that lax packaging accentuates the overall roundness of form.

Baby movements are notably clumsy, an amusing combination of jerky and delayed, because learning to coordinate the body's many bilateral sets of large and fine muscle groups requires years of practice. On starting to walk, toddlers struggle continuously to balance themselves between left foot and right, and so the toddler gait consists as much of lateral movement as of any forward momentum.

Researchers who study animals beloved by the public appreciate the human impulse to nurture anything even remotely babylike, though they are at times taken aback by people's efforts to identify with their preferred species.

Take penguins as an example. Some people are so wild for the creatures, said Michel Gauthier-Clerc, a penguin researcher in Arles, France, "they think penguins are mammals and not birds." They love the penguin's upright posture, its funny little tuxedo, the way it waddles as it walks. How like a child playing dress-up!

Endearing as it is, Dr. Gauthier-Clerc explained that the apparent awkwardness of the penguin's march had nothing to do with clumsiness or uncertain balance. Instead, he said, penguins waddle to save energy. A side-to-side walk burns fewer calories than a straightforward stride, and for birds that fast for months and live in a frigid climate, every calorie counts.

As for the penguin's maestro garb, the white front and black jacket suits its aquatic way of life. While submerged in water, the penguin's dark backside is difficult to see from above, camouflaging the penguin from potential predators of air or land. The white chest, by contrast, obscures it from below, protecting it against carnivores and allowing it to better sneak up on fish prey.

The giant panda offers another case study in accidental cuteness. Although it is a member of the bear family, a highly carnivorous clan, the giant panda specializes in eating bamboo.

As it happens, many of the adaptations that allow it to get by on such a tough diet contribute to the panda's cute form, even in adulthood. Inside the bear's large, rounded head, said Lisa Stevens, assistant panda curator at the National Zoo, are the highly developed jaw muscles and the set of broad, grinding molars it needs to crush its way through some 40 pounds of fibrous bamboo plant a day.

When it sits up against a tree and starts picking apart a bamboo stalk with its distinguishing pseudo-thumb, a panda looks like nothing so much like Huckleberry Finn shucking corn. Yet the humanesque posture and paws again are adaptations to its menu. The bear must have its "hands" free and able to shred the bamboo leaves from their stalks.

The panda's distinctive markings further add to its appeal: the black patches around the eyes make them seem winsomely low on its face, while the black ears pop out cutely against the white fur of its temples.

As with the penguin's tuxedo, the panda's two-toned coat very likely serves a twofold purpose. On the one hand, it helps a feeding bear blend peacefully into the dappled backdrop of bamboo. On the other, the sharp contrast between light and dark may serve as a social signal, helping the solitary bears locate each other when the time has come to find the perfect, too-cute mate.

Scientist at Work | Shannon Lee Dawdy
Archaeologist in New Orleans Finds a Way to Help the Living
By JOHN SCHWARTZ, The New York Times, January 3, 2006

NEW ORLEANS -"That's a finger bone."

Shannon Lee Dawdy kneeled in the forlorn Holt graveyard to touch a thimble-size bone poking up out of the cracked dirt. She examined it without revulsion, with the fascination of a scientist and with the sadness of someone who loves New Orleans.

Dr. Dawdy, a 38-year-old assistant professor of anthropology at the University of Chicago, is one of the more unusual relief workers among the thousands who have come to the devastated expanses of Louisiana, Mississippi and Texas in the aftermath of Hurricanes Katrina and Rita. She is officially embedded with the Federal Emergency Management Agency as a liaison to the state's historic preservation office.

Her mission is to try to keep the rebuilding of New Orleans from destroying what is left of its past treasures and current culture.

While much of the restoration of the battered Gulf Coast is the effort of engineers and machines, the work of Dr. Dawdy, trained as an archaeologist, an anthropologist and a historian, shows that the social sciences have a role to play as well. "It's a way that archaeology can contribute back to the living," she said, "which it doesn't often get to do."

Holt cemetery, a final resting place for the city's poor, is just one example of what she wants to preserve and protect.

Other New Orleans graveyards have gleaming mausoleums that keep the coffins above the marshy soil. But the coffins of Holt are buried, and the ground covering many of them is bordered with wooden frames marked with makeshift headstones.

Mourners decorate the graves with votive objects: teddy bears for children and an agglomeration of objects, including ice chests, plastic jack-o'-lanterns and chairs, on the graves of adults. There is the occasional liquor bottle.

It is part of the soul of New Orleans, a city that through history has had strong ties to its dead. Dr. Dawdy calls it a prime example of "the amazing improvisational impulse of New Orleans," which creates beautiful things and powerful feelings from the everyday.

Dr. Dawdy looked across the ruined graveyard. Holt was a place she knew well and loved, she said, and when she first saw it after the storm, she broke down and cried.

"It made me realize that it's that ephemeral folk expression in New Orleans that is gone," she said, "and that probably, rebuilding efforts may erase."

Many of the objects on the graves were washed away by the storm, or shifted from one part of the graveyard to another. Dr. Dawdy has proposed treating the site as archaeologists would an ancient site in which objects have been exposed on the surface by erosion.

Before the hurricanes, the cemetery was often busy, a hub of activity on All Souls' Day, when people came to freshen the grave decorations.

"The saddest thing to me now was how few people we see," she said, looking at the empty expanse and the scarred live oaks. "I realize we're having enough trouble taking care of the living," she added, but the lack of activity in a city normally so close to the spirits of the past "drove home how far out of whack things are."

There is evidence of recent visits: blindingly white gravel sits atop some graves, and a fresh bouquet sits on the grave of Andrew P. Sherman, who was born in September 1924 and died in 1968. Dr. Dawdy picks up the bouquet and checks the tag: it was purchased on Nov. 6. "Here's archaeological dating for you," she said with a small smile.

Treating Holt as an archaeological site mean the government should not treat the votive artifacts as debris, she said, but as the religious artifacts that they are, with some effort to restore the damaged site, to find the objects and at least record where they came from.

FEMA simply tries to clean up damaged areas, and its Disaster Mortuary Operational Response Teams - called Dmort- deal with the bodies of the dead and address problems in cemeteries that might lead to disease.

If such places are destroyed, Dr. Dawdy said, "then people don't feel as connected here." She added that they might be more willing to come back to a damaged city if they felt they were returning to a recognizable home.

Though she has deep emotional ties to New Orleans, Dr. Dawdy was born in Northern California. She came here in 1994 to write her master's thesis for the College of William & Mary, and, "I wrote it all day," she said. "If I had written a minimum of five pages, I could come out for a parade at night." Over the eight weeks it took to finish the project, she said: "I fell in love with New Orleans. I really consider it the home of my heart."

She started a pilot program at the University of New Orleans, working with city planners and grants for research projects that involved excavation, oral history and hands-on work with the city to safeguard its buried treasures.

She left that job to earn a double doctorate at the University of Michigan in anthropology and history that focused on French colonial times in New Orleans, then landed a coveted faculty position at the University of Chicago. She now lives in Chicago with her husband, Dan McNaughton, and their 5-year-old son.

Jean Comaroff, the head of the anthropology department at the University of Chicago, said in an e-mail message that it was only natural to be supportive of Dr. Dawdy's efforts to help New Orleans.

"I could think of no one better to serve FEMA in this role," she wrote. "The threat is great that much that was unique about New Orleans as a social and cultural world - qualities that are at once creative, poignant and fragile - will be lost in its reconstruction. Those of us who value these qualities feel moved to do all we can to conserve them."

Even before Hurricane Katrina, Dr. Dawdy had found ways to return to New Orleans. In 2004, she made an intriguing discovery while researching a possible archaeological site under an old French Quarter parking garage slated for demolition. Property records and advertisements from the 1820's said that the site had been the location of a hotel with an enticing name: the Rising Sun Hotel.

Dr. Dawdy found a January 1821 newspaper advertisement for the hotel in which its owners promised to "maintain the character of giving the best entertainment, which this house has enjoyed for twenty years past."

It went on: "Gentlemen may here rely upon finding attentive Servants. The bar will be supplied with genuine good Liquors; and at the Table, the fare will be of the best the market or the season will afford."

The historical record made her think that the building might have served as something more interesting than a mere hotel, a brothel perhaps. Digging under the garage, she found an unusual number of liquor bottles and rouge pots.

For Dr. Dawdy, it was a lucky break, the kind of find that can make a reputation. "Can you prove archaeologically is this a brothel?" she asked. "I can't prove it with a yes or no answer."

Nor can she say with certainty that this Rising Sun was the inspiration for "House of the Rising Sun," the famous song first recorded in 1937 by Alan Lomax, a musicologist and folklorist.

"I love the ambiguity of it all," Dr. Dawdy said.

New Orleans, she noted, has always been known for its libertine lifestyle. The French all but abandoned the city as its colony around 1735 as being unworthy of the nation's support as a colony. Novels like "Manon Lescaut" portrayed the city as a den of iniquity and corruption, and across Europe, "they thought the locals were basically a bunch of rogues, immoral and corrupt," Dr. Dawdy said.

She added that she saw parallels to today, as some skepticism emerges about rebuilding the city. Dr. Dawdy characterized that posture as, "Those people in New Orleans aren't worth saving, because they're all criminals anyway."

But even if the devastation makes it hard to envision the road back, the city, she said, is worth fighting for.

"The thing about New Orleans that gives me hope is they are so tied to family, place, history," Dr. Dawdy said. "If anyone is going to stick it out, out of a sense of history, out of a sense of tradition, it is New Orleans."

Evidence Found for Canals That Watered Ancient Peru
By JOHN NOBLE WILFORD, The New York Times, January 3, 2006

In the Andean foothills of Peru, not far from the Pacific coast, archaeologists have found what they say is evidence for the earliest known irrigated agriculture in the Americas.

An analysis of four derelict canals, filled with silt and buried deep under sediments, showed that they were used to water cultivated fields 5,400 years ago, in one case possibly as early as 6,700 years ago, archaeologists reported in a recent issue of The Proceedings of the National Academy of Sciences.

Other scholars hailed the discovery as adding a new dimension to understanding the origins of civilization in the Andes. The canals are seen as the long-sought proof that irrigation technology was critical to the development of the earliest Peruvian civilization, one of the few major cultures in the ancient world to rise independent of outside influence.

It was assumed that by 4,000 years ago, perhaps 1,000 years earlier, large-scale irrigation farming was well under way in Peru, as suggested by the indirect evidence of urban ruins of increasing size and architectural distinction. Their growth presumably depended on irrigation in the arid valleys and hills descending to coastal Peru. But the telling evidence of the canals had been missing.

Then Tom D. Dillehay, an archaeologist at Vanderbilt University, started nosing around the Zaña Valley, about 40 miles from the ocean and more than 300 miles north of Lima.

On the south side of the Nanchoc River, he and his team uncovered traces of the four canals, narrow and shallow, lined with stones and pebbles, extending from less than a mile to more than two miles in length. The canals ran near remains of houses, buried agricultural furrows, stone hoes and charred plants, including cotton, wild plums, beans and squash.

"The Zaña Valley canals are the earliest known in South America," Dr. Dillehay's team wrote in the journal article. He added, by e-mail from Chile, that they were the "earliest in the Americas."

The initial discovery was made in 1989, but it took years of further excavations, radiocarbon dating and other analysis before Dr. Dillehay felt ready to announce the find.

"We wanted to make sure that the dates were correct and to find more early canals," Dr. Dillehay said. "There are now four sites with canals and probably more."

The authors of the journal article - Dr. Dillehay, Herbert Eling of the National Institute of Anthropology and History in Mexico and Jack Rossen of Ithaca College - said the system appeared to be a small-scale example of organized irrigation technology that "accompanied a mixed economy of incipient agriculturalists, plant collectors and hunters."

They reported finding no evidence of a centralized bureaucracy to manage the canals or mechanical devices to control flow rates. But the people of the valley understood elementary hydrology. They laid out the canals to use gravity to deliver river water down gentle slopes to the cultivated fields.

Craig Morris, a specialist in Peru archaeology at the American Museum of Natural History, who did not take part in the research, said, "Their use of slope and management of water flow shows again that ancient people were a lot smarter and more observant than we often give them credit for."

Jonathan Haas, an archaeologist at the Field Museum in Chicago who has excavated urban sites elsewhere in Peru's coastal valleys, called the canal discovery "a difficult and brilliant piece of work."

In their own excavations, Dr. Haas and Winifred Creamer of Northern Illinois University have uncovered remains of urban centers of a complex agricultural society that flourished 5,000 years ago in valleys in a region known as Norte Chico, or Little North. Such an arid region would have had to have irrigation to have agriculture, especially on an apparently large and prosperous scale.

Dr. Haas said the new discovery appeared to show the early irrigation technology that the people of Norte Chico then adopted and expanded to "bring about a cultural transformation" 400 years later.

Lax Oversight Found in Tests of Gene-Altered Crops
By ANDREW POLLACK, The New York Times, January 3, 2006

The Department of Agriculture has failed to regulate field trials of genetically engineered crops adequately, raising the risk of unintended environmental consequences, according to a stinging report issued by the department's own auditor.

The report, issued late last month by the department's Office of Inspector General, found that biotechnology regulators did not always notice violations of their own rules, did not inspect planting sites when they should have and did not assure that the genetically engineered crops were destroyed when the field trial was done.

In many cases, the report said, regulators did not even know the locations of field trials for which they granted permits.

The regulatory branch "lacks basic information about the field test sites it approves and is responsible for monitoring, including where and how the crops are being grown, and what becomes of them at the end of the field test," the report said.

The audit results are likely to renew calls by environmental groups for tighter regulations. "Over all, I thought the report was devastating," said Margaret Mellon, director of the food and environment program at the Union of Concerned Scientists in Washington.

Critics say genetically engineered crops could cause environmental harm, if, say, a gene for herbicide resistance spread to weeds, making them harder to kill.

In addition, the critics say, there could be harm to public health if a crop genetically engineered to produce a pharmaceutical or industrial chemical, for instance, accidentally found its way into the food supply.

The audit did not find any instances of known harm to public health or the environment.

However, the report said that weaknesses in regulations and in the internal management controls at the Department of Agriculture "increase the risk that genetically engineered organisms will inadvertently persist in the environment before they are deemed safe to grow without regulation."

In a written response, the Agriculture Department's Animal and Plant Health Inspection Service, which regulates biotech field trials, said that it was already taking steps to adopt 23 of the 28 recommendations made by the inspector general, and that more changes were on the way.

W. Ron DeHaven, the administrator of the service, known as Aphis, wrote in the response, "Since 1987, Aphis has safely regulated G.E. organisms and provided oversight and enforcement for over 10,000 field tests with no demonstrable negative environmental impacts having arisen from these tests."

A biotechnology industry spokeswoman said the report would have little effect because changes were already under way. "This is a report that was pretty much obsolete before it was ever published," said the spokeswoman, Lisa Dry of the Biotechnology Industry Organization.

The inspector general's office, however, said that further improvements would be required beyond those already planned.

Field trials are used to test experimental genetically engineered crops. Crop developers proposed to use 67,000 acres for such tests in 2004, up from 8,700 acres in 1994.

Once crops have proved themselves in field trials, the Agriculture Department can deregulate them, and seeds and harvested crops can be sold pretty much like any other seeds and crops.

The main varieties of genetically modified corn, cotton and soybeans grown in the United States have been deregulated.

The audit was conducted from May 2003 to April 2005 and involved visits to 91 field test sites as well as looking at records. The report said auditors found 13 instances of violations of rules at 11 of those sites.

One of the most controversial areas of agricultural biotechnology involves genetically engineering crops to produce pharmaceuticals or industrial chemicals. The Agriculture Department has stricter requirements for those crops than for genetically modified crops meant for food or animal feed.

However, the new report said the department often failed to enforce those stricter requirements. In most cases the auditors checked, the sites were not inspected five times each during field tests, as the department had promised. Nor were they inspected twice after the trial to make sure the crop was destroyed and the field fallow.

The report said that in two cases large harvests of pharmaceutical crops remained in storage for more than a year after the field test ended with regulators' not knowing of the storage facility or approving it.

Vital Signs:Patterns: Home Remedies: A Matter of Culture, Not Money
By ERIC NAGOURNEY, The New York Times, January 3, 2006

A tendency among older blacks and American Indians to turn to home remedies to treat illness appears unrelated to personal finances or access to health care, a new study has found.

Writing in the new issue of The American Journal of Health Behavior, the researchers say the varying uses of the treatments among ethnic groups seem to reflect, above all, cultural differences.

Home remedies were commonly used by most of the 700 people 65 and older to whom the researchers spoke in two rural North Carolina communities. They often involved foods - baking soda, for example, or yeast, teas and whiskey. But they also included tobacco, Epsom salts and kerosene.

Still, the remedies were most prevalent among nonwhites. Hoping to learn why, the researchers, led by Joseph G. Grzywacz of Wake Forest University School of Medicine, asked interview subjects about their income and about how easy it was for them to obtain medical care. These factors, the researchers found, seemed to play only a small role in the decision to use home remedies.

"It's not about access," Dr. Grzywacz said. "It's not about money."

He also said the researchers had not set out to assess the safety or benefit of the remedies. "Whether that's a good thing or a bad thing, we're not trying to make any claims on that," he said.

But doctors treating patients who are using home remedies should be aware of the practices, he said, and should know which groups of patients are most likely to be doing so.