Personal Health Care

Among the many great mysteries of autism is this: Where are all the adults with the disorder? In California, for instance, about 80% of people identified as having an autism spectrum disorder (ASD) are 18 or under. Studies by the Centers for Disease Control and Protection (CDC) indicate that about 1 in 150 children in the U.S. have autism, but despite the fact that autism is by definition a lifelong condition, the agency doesn't have any numbers for adults. Neither has anyone else. Until now.

On Sept. 22, England's National Health Service (NHS) released the first study of autism in the general adult population. The findings confirm the intuitive assumption: that ASD is just as common in adults as it is in children. Researchers at the University of Leicester, working with the NHS Information Center found that roughly 1 in 100 adults are on the spectrum — the same rate found for children in England, Japan, Canada and, for that matter, New Jersey.

This finding would also appear to contradict the commonplace idea that autism rates have exploded in the two decades. Researchers found no significant differences in autism prevalence among people they surveyed in their 20s, 30s, 40s, right up through their 70s. "This suggests that the factors that lead to developing autism appear to be constant," said Dr. Terry Brugha, professor of psychiatry at the University of Leicester and lead author of the study. "I think what our survey suggests doesn't go with the idea that the prevalence is rising."

In England, where there is widespread suspicion that the childhood vaccine for measles, mumps and rubella has led to an explosion in autism cases, the study was hailed as part of a growing body of evidence that the vaccine, which was introduced in the 1988, is not to blame.

Brugha's study was part of a larger national survey of psychiatric disorders among adults. In the first phase, researchers conducted 90-minute interviews with 7,461 people in 4,000 randomly selected British households; the interview included a 20-item questionnaire designed to screen for autism. (Sample yes-or-no questionnaire items: I find it easy to make friends. I would rather go to a party than the library. I particularly enjoy reading fiction.) Based on their answers in the first phase, investigators further assessed 618 individuals, using a battery of psychiatric measures, including a state-of-the art autism diagnostic tool. (About 200 of these participants had been selected for scoring high on the autism screen; the rest had been selected to sample for other disorders.) In the second phase, researchers identified 19 adults with ASD. But had they been able to evaluate all 7,461 in the survey, they estimate that they would have found 72 cases, or roughly 1% of the total.

One limitation of the study is its relatively small size, says Brugha. Being the first of its kind, it also needs to be confirmed by other studies. Another issue, notes Richard Roy Grinker, an autism researcher and professor of anthropology at George Washington University, who was not involved in the work, is that the study looked only at adults in the general population. Had it included people living in institutions, which is where the most severely autistic adults are likely to be, the estimated rate of ASD may have been even higher than 1%.

Michael Rosanoff, an epidemiology specialist with Autism Speaks, emphasizes that "the small sample size for estimating prevalence requires caution about interpreting this finding on a population-based scale."

Despite its limits, the new study does begin to fill in the profile of high-functioning adults who are on the spectrum but living in an ordinary home in the community. Researchers found that they are primarily male and unmarried: about 1.8% of men surveyed were on the spectrum — among never-married, single men, an estimated 4.5% had ASD — compared with just 0.2% of women. (Brugha notes, however, that autism screening tools may be poorly adapted for identifying autism in adult females.) People with autism are less likely than average to have finished college but about as likely to be employed. Only 0.2% of adults who had finished college were on the spectrum, but the rate was 10 times higher among those without a high school degree. And, in contrast with people with depression or anxiety disorders, autistic adults were unlikely be receiving any sort of mental health services.

Why has it taken so long to do a study of this sort? For one thing, you need an enormous sample size — at an enormous cost — to find significant numbers of people with autism. Second, it's more difficult to detect autism in adults than in children. Children often have glaring symptoms, like delays in learning to speak, extreme social withdrawal and terrible tantrums. Less is known about how autism looks in adults. "To diagnose autism, you need to have good information on people's behavior," says Brugha. "It's much more straightforward to get that with children because you've got parents and teachers as observers. Adults with autism are not the best people to describe their own behavior."

The Irish-born psychiatrist and epidemiologist says he sees a lot of adults with ASD in his own clinical practice, and "they have so much difficulty saying what their own difficulties are." He suspects that this lack of insight and inability to communicate emotional issues also reduces their ability to seek professional help.

Efforts to identify and help adults with ASD have lagged far behind efforts to help children. And yet, Brugha notes that just having an ASD diagnosis to explain their troubles can be enormously beneficial to his adult patients, who often struggle with relationships at home and at work because of difficulty reading social cues. "Once you help them to understand that they are not the only person on the planet who is like this, and help their families understand, it can be a breakthrough. People also have a better chance of staying in their work, if their employer understands why they are the way they are." Moreover, Brugha says it is not expensive to provide services to adults with relatively mild autism. "The cost of treating a child with autism is phenomenally high. We are not talking about this. We are talking about support, helping people adapt their lives" with help from a social worker.

Grinker, who has a teenage daughter with autism, finds the study to be in some ways comforting. "I would think that a study like this would encourage people that children with autism could grow up and have futures that are meaningful and that they are not going to end up in institutions."

Was it an omen when the power went out halfway through the Governors' Global Climate Summit? The 1,200 representatives from more than 70 states, provinces and countries in attendance at California Gov. Arnold Schwarzenegger's global warming conference were about to convene for panels on the green economy and clean-tech innovation, when the lights suddenly went dark at the Hyatt Regency Century Plaza Hotel in Los Angeles. There was a bit of confusion (given California's state budget woes, one had to wonder whether the power bill was past due), but soon enough the attendees shrugged and continued on with the conference. Having fought to put climate change on the global agenda for years — and now representing perhaps the world's best hope for confronting climate change — a brief blackout wasn't going to stop them.

This is the second time Schwarzenegger has held a global warming conference focused on what state and local governments can do about climate change, and it couldn't come at a more appropriate time. While Washington under President George W. Bush all but ignored climate change, California — with the Republican Schwarzenegger sometimes leading and sometimes following — embarked on its own green path, passing a landmark carbon-emissions cap for the state in 2006 and aggressively promoting renewable energy. Today, California's clean-tech sector is a rare bright spot in a state that is struggling with economic problems. California is where "technology met policy," said Terry Tamminen, the former secretary of the California Environmental Protection Agency and now a senior fellow for climate policy at the New America Foundation. (See pictures of the world's most polluted places.)

Due in no small part to prodding by California and other states with progressive governors, attitudes have changed in Washington. But Congress continues to dither over cap and trade, and California is moving ahead. On Sept. 15, Schwarzenegger signed an executive order requiring that the state get 33% of its electricity from renewable sources by 2020 — well above the 15% national standard that current climate bills circulating in Congress would require. California is not alone: more than half the states in the U.S. have similar renewable energy standards, and states in the West and the Northeast have begun to form regional carbon cap-and-trade programs. "This is an incredible opportunity to create the economies of the future and we must seize it," Schwarzenegger said in his opening speech at the summit on Sept. 30. "We are calling on our national governments to recognize the innovative solutions we have to offer." (Watch TIME's video "The Governors' Global Climate Summit.")

The governors who have gathered in Los Angeles are pushing from the bottom up, demonstrating that there is political will to deal with climate change. Ultimately, of course, it will be the national governments in Washington, London and Beijing, among other places, that will take part in the upcoming U.N. climate summit in Copenhagen and shape how the world takes on global warming. But the vast majority of that response — whether it means shoring up cities for sea level rise or tightening green building codes — will need to be carried out at the state and city level, the governors in L.A. noted. The summit "is part of that global groundswell that perceives the threats from climate change, but also the inordinate opportunities if the world acts now and in concert to transit to a low carbon, green economy," said Achim Steiner, executive director for the U.N. Environment Program.

To that end, local governments are forging connections among themselves. A main focus of this year's Governors' summit is deforestation, another key issue in the run-up to Copenhagen. Eleven governors from states and provinces in Brazil, Indonesia, Canada and the U.S. issued a collective call for national governments to stop the loss of tropical forests, which accounts for up to one-fifth of global carbon emissions. On Friday, the last day of the summit, local leaders will sign agreements to work together on clean transportation and climate adaptation. With prospects for a complete treaty in Copenhagen diminishing — due largely to foot-dragging in Washington — what's needed now, as Schwarzenegger repeated at the summit, is "action, action, action." Even if it has to be done in the dark.

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What parent hasn't used candy to pacify a cranky child or head off a brewing tantrum? When reasoning, threats and time-outs fail, a sugary treat often does the trick. But while that chocolate-covered balm may be highly effective in the short term, say British scientists, it may be setting youngsters up for problem behavior later. According to a new study, kids who eat too many treats at a young age risk becoming violent in adulthood.

The research was led by Simon Moore, a senior lecturer in Violence and Society Research at Cardiff University in the U.K., who specializes in the study of vulnerable youngsters. Moore had been investigating the factors that lead children to commit serious crimes, when, during the course of his work, he discovered that "kids with the worst problems tend to be impulsive risk takers, and that these kids had terrible diets — breakfast was a Coke and a bag of chips," he says. (See nine kid foods to avoid.)

Intrigued by this association, Moore turned to the British Cohort Study, a long-term survey of 17,000 people born during a one-week period in April 1970. That study included periodic evaluations of many different aspects of the growing children's lives, such as what they ate, certain health measures and socioeconomic status. Moore plumbed the data for information on kids' diet and their later behavior: at age 10, the children were asked how much candy they consumed, and at age 34, they were questioned about whether they had been convicted of a crime. Moore's analysis suggests a correlation: 69% of people who had been convicted of a violent act by age 34 reported eating candy almost every day as youngsters; 42% of people who had not been arrested for violent behavior reported the same. "Initially we thought this [effect] was probably due to something else," says Moore. "So we tried to control for parental permissiveness, economic status, whether the kids were urban or rural. But the result remained. We couldn't get rid of it." (See the 25 crimes of the century.)

In other words, regardless of other environmental and lifestyle factors, like family-income level, parenting style or children's level of education, the data suggested it was only the frequency of confectionery consumption in childhood that strongly predicted adult violence. "The key message is that this study really raises more questions than answers," says Moore. (See the top 10 food trends of 2008.)

One of those questions is whether sweets themselves contain compounds that promote antisocial and aggressive behavior, or whether the excessive eating of sweets represents a lack of discipline in childhood that translates to poor impulse control in adulthood. Moore is leaning toward the latter. It's possible that children who are given sweets too frequently never learn how to delay gratification — that is, they never develop enough patience to wait for things they want, leading to impulsivity in adulthood. It's also possible that children who are poorly behaved from the start tend to get more candy. (Read "Why Media Could Be Bad for Your Child's Health.")

Moore acknowledges that there is also some intriguing data suggesting that diet itself may have a profound effect on behavior. A University of Oxford researcher recently published controversial findings hinting that prisoners who were fed vitamin supplements — and therefore presumably getting well-balanced nutrition — had lower rates of disciplinary events and aggressive outbursts than a control group who were given placebo pills. While the association is preliminary, says Moore, "I think looking at diet is a fairly novel way to think of behavior over the life course."

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Figuring out the story of human origins is like assembling a huge, complicated jigsaw puzzle that has lost most of its pieces. Many will never be found, and those that do turn up are sometimes hard to place. Every so often, though, fossil hunters stumble upon a discovery that fills in a big chunk of the puzzle all at once — and simultaneously reshapes the very picture they thought they were building.

The path of just such a discovery began in November 1994 with the unearthing of two pieces of bone from the palm of a hominid hand in the dusty Middle Awash region of Ethiopia. Within weeks, more than 100 additional bone fragments were found during an intensive search-and-reconstruction effort that would go on for the next 15 years and culminate in a key piece of evolutionary evidence revealed this week: the 4.4 million–year–old skeleton of a likely human ancestor known as Ardipithecus ramidus (abbreviated Ar. ramidus). (See the top 10 scientific discoveries of 2008.)

In a series of studies published in the Oct. 2 special issue of Science — 11 papers by a total of 47 authors from 10 countries — researchers unveiled Ardi, a 125-piece hominid skeleton that is 1.2 million years older than the celebrated Lucy (Australopithecus afarensis) and by far the oldest one ever found. Tim White of the University of California, Berkeley, a co-leader of the Middle Awash research team that discovered and studied the new fossils, says, "To understand the biology, the parts you really want are the skull and teeth, the pelvis, the limbs and the hands and the feet. And we have all of them."

That is the beauty of Ardi — good bones. The completeness of Ardi's remains, as well as the more than 150,000 plant and animal fossils collected from surrounding sediments of the same time period, has generated an unprecedented amount of intelligence about one of our earliest potential forebears. The skeleton allows scientists to compare Ardipithecus directly with Lucy's genus, Australopithecus, its probable descendant. Perhaps most important, Ardi provides clues to what the last common ancestor shared by humans and chimps might have looked like before their lineages diverged about 7 million years ago. (See pictures of ancient skeletons.)

Ardi is the earliest and best-documented descendant of that common ancestor. But despite being "so close to the split," says White, the surprising thing is that she bears little resemblance to chimpanzees, our closest living primate relatives. The elusive common ancestor's bones have never been found, but scientists, working from the evidence available — especially analyses of Australopithecus and modern African apes — envisioned Great-Great-Grandpa to have looked most nearly like a knuckle-walking, tree-swinging ape. But "[Ardi is] not chimplike," according to White, which means that the last common ancestor probably wasn't either. "This skeleton flips our understanding of human evolution," says Kent State University anthropologist C. Owen Lovejoy, a member of the Middle Awash team. "It's clear that humans are not merely a slight modification of chimps, despite their genomic similarity." (See "Darwin and Lincoln: Birthdays and Evolution.")

So what does that mean? Based on Ardi's anatomy, it appears that chimpanzees may actually have evolved more than humans — in the scientific sense of having changed more over the past 7 million years or so. That's not to say Ardi was more human-like than chimplike. White describes her as an "interesting mosaic" with certain uniquely human characteristics: bipedalism, for one. Ardi stood 47 in. (120 cm) tall and weighed about 110 lb. (50 kg), making her roughly twice as heavy as Lucy. The structure of Ardi's upper pelvis, leg bones and feet indicates she walked upright on the ground, while still retaining the ability to climb. Her foot had an opposable big toe for grasping tree limbs but lacked the flexibility that apes use to grab and scale tree trunks and vines ("Gorilla and chimp feet are almost like hands," says Lovejoy), nor did it have the arch that allowed Australopithecus and Homo to walk without lurching side to side. Ardi had a dexterous hand, more maneuverable than a chimp's, that made her better at catching things on the ground and carrying things while walking on two legs. Her wrist, hand and shoulder bones show that she wasn't a knuckle walker and didn't spend much time hanging or swinging ape-style in trees. Rather, she moved along branches using a primitive method of palm-walking typical of extinct apes. "[Ardi is] a lovely Darwinian creature," says Penn State paleoanthropologist Alan Walker, who was not involved in the discovery. "It has features that are intermediate between the last common ancestor and australopithecines."

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Scientists know this because they've studied not only Ardi's fossils but also 110 other remnants they uncovered, which belonged to at least 35 Ar. ramidus individuals. Combine those bones with the thousands of plant and animal fossils from the site and they get a remarkably clear picture of the habitat Ardi roamed some 200,000 generations ago. It was a grassy woodland with patches of denser forest and freshwater springs. Colobus monkeys chattered in the trees, while baboons, elephants, spiral-horned antelopes and hyenas roamed the terrain. Shrews, hares, porcupines and small carnivores scuttled in the underbrush. There were an assortment of bats and at least 29 species of birds, including peacocks, doves, lovebirds, swifts and owls. Buried in the Ethiopian sediments were hackberry seeds, fossilized palm wood and traces of pollen from fig trees, whose fruit the omnivorous Ar. ramidus undoubtedly ate.

This tableau demolishes one aspect of what had been conventional evolutionary wisdom. Paleoanthropologists once thought that what got our ancestors walking on two legs in the first place was a change in climate that transformed African forest into savanna. In such an environment, goes the reasoning, upright-standing primates would have had the advantage over knuckle walkers because they could see over tall grasses to find food and avoid predators. The fact that Lucy's species sometimes lived in a more wooded environment began to undermine that theory. The fact that Ardi walked upright in a similar environment many hundreds of thousands of years earlier makes it clear that there must have been another reason.

No one knows what that reason was, but a theory about Ardi's social behavior may hold a clue. Lovejoy thinks Ar. ramidus had a social system found in no other primates except humans. Among gorillas and chimps, males viciously fight other males for the attention of females. But among Ardipithecus, says Lovejoy, males may have abandoned such competition, opting instead to pair-bond with females and stay together in order to rear their offspring (though not necessarily monogamously or for life). The evidence of this harmonious existence comes from, of all things, Ardipithecus' teeth: its canine teeth are relatively stubby compared with the sharp, dagger-like upper fangs that male chimps and gorillas use to do battle. "The male canine tooth," says Lovejoy, "is no longer projecting or sharp. It's no longer weaponry."

That suggests that females mated preferentially with smaller-fanged males. In order for females to have had so much power, Lovejoy argues, Ar. ramidus must have developed a social system in which males were cooperative. Males probably helped females, and their own offspring, by foraging for and sharing food, for example — a change in behavior that could help explain why bipedality arose. Carrying food is difficult in the woods, after all, if you can't free up your forelimbs by walking erect. (Read "Ida: Humankind's Earliest Ancestor! [Not Really.)]")

Deducing such details of social behavior is, admittedly, speculative — and several researchers are quick to note that some of the authors' other major conclusions need further discussion as well. One problem is that some portions of Ardi's skeleton were found crushed nearly to smithereens and needed extensive digital reconstruction. "Tim [White] showed me pictures of the pelvis in the ground, and it looked like an Irish stew," says Walker. Indeed, looking at the evidence, different paleoanthropologists may have different interpretations of how Ardi moved or what she reveals about the last common ancestor of humans and chimps.

But Science doesn't put out special issues very often, and the extraordinary number and variety of fossils described in these new papers mean that scientists are arguing over real evidence, not the usual single tooth here or bit of foot bone there. "When we started our work [in the Middle Awash]," says White, "the human fossil record went back to about 3.7 million years." Now scientists have a trove of information from an era some 700,000 years closer to the dawn of the human lineage. "This isn't just a skeleton," he says. "We've been able to put together a fantastic, high-resolution snapshot of a period that was a blank." The search for more pieces continues, but the outlines of the puzzle, at least, are coming into focus.

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Earning a driver's license is a modern-day right of passage for American teens — and for their fretful parents. But even though it marks teenagers' first major step toward independence, researchers say parents can still wield a lot of influence on how safely — or hazardously — that transition unfolds.

Scientists at the Children's Hospital of Philadelphia report in two studies that parents can significantly reduce the accident rate among teens simply by talking with them about driving and enforcing rules for safety — much the way, as has been shown, parents can reduce the risk of substance abuse through conversations about alcohol and drugs. In fact, driving should be considered as dangerous as alcohol and drugs, the scientists say. In 2005, the latest year for which the government has statistics on teen driving, adolescent deaths made up 12% of all deaths from car accidents, and 400,000 teens required treatment in an emergency department due to a motor-vehicle crash. (See pictures of a diverse group of American teens.)

At first blush, the correlation between parental oversight and teen accident rates may seem obvious, but the research team was surprised by how much influence parental monitoring and communication actually had. In the new analysis, based on data from the National Young Driver Survey, a study of 5,665 students in grades 9 through 12, lead author Kenneth Ginsburg found that the safest drivers were those who reported that their parents had imposed strict rules on driving and also provided warm and supportive explanations for their rules. "This absolutely backs up what is intuitively known about parenting — that more-engaged parents are more effective," says Ginsburg. "The bottom line is that you have got to talk to your kids in ways that they know this is about safety and not control. If you make up rules and they think that you are invading their personal space or that in some way you are going to stop their road to independence, then they will reject the rules."

The safest drivers in the study had half the crash risk of students without parental surveillance in the year preceding the survey. The aggressively supervised teens were also 50% less likely to speed, 71% less likely to drive after drinking and 29% less likely to use their cell phones while on the road, compared with their friends who reported having more-permissive parents.

In a second study, Ginsburg and another group reanalyzed the same data set and found that teens who considered themselves to be the primary driver of a vehicle were twice as likely to get into accidents as those who shared responsibility for a car or had to report to their parents for each use. In the survey, 70% of kids reported that they were the main driver of a car, regardless of whether they owned the vehicle. This perception, says Ginsburg, can promote more irresponsible driving habits. "Kids who have easy access to the keys are probably less likely to have those protective conversations with their parents and talk about setting rules," he says. "If they don't have to come home and return the keys or the car to someone, they are less likely to feel that what they are doing is closely watched, and they are less likely to watch or monitor themselves."

Most parents would probably say they talk to their teens about responsible driving, but Ginsburg notes specific techniques that the parents of the safest teen drivers tend to use. These include setting firm rules and boundaries for driving — such as no speeding, no talking on a cell phone or texting while on the road and no driving while intoxicated. Parents of safe drivers also tend to make it a point to explain to their children that the reason for their rules is to ensure the child's safety. “They have to see the rules as a safety issue, so they choose to do the right thing," he says. (Read "Distracted Driving: Should Talking, Texting Be Banned?")

Ginsburg also suggests that parents of new drivers adopt a version of the graduated licensing program that many states have in place. Rules include requiring a certain amount of experience before allowing teens to drive in bad weather or after dark during their first licensed year and prohibiting them from driving with other teens until they can demonstrate their ability to concentrate on the road and not get distracted by passengers. "Driving is such a potentially dangerous thing that we have to make it so that the car is not the place where teens test their independence," Ginsburg says. "We need to transform the car from being a place where they rebel or act out their freedom fantasies to becoming a place where they demonstrate responsibility. Wise parents can do that."

Read "Putting Limits on Teen Drivers."

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