Can it render good judgment on genetically engineered food when only a quarter can define a molecule?
And can Americans assess competing medical claims when only a third show a good understanding of the scientific process?
Experts see cause for concern in the latest report card on American scientific understanding.
According to the study by the National Science Foundation:
• Only 45 percent could define "DNA," the substance carrying the inherited genetic code.
• 22 percent could define "molecule," the basic unit of a chemical compound.
• 45 percent knew lasers don't work by focusing sound waves. Lasers use light waves.
• 48 percent knew electrons are smaller than atoms.
• 48 percent knew it's not true that the earliest humans lived at the same time as dinosaurs.
Dinosaurs and humans missed each other by some 60 million years. But "we're interviewing people on the phone who grew up watching 'Flintstones,"' said Melissa Pollak, senior analyst at the foundation.
Americans did better on some other questions. Ninety-four percent knew cigarette smoking causes lung cancer, for example, and about three-quarters knew that some radioactivity is naturally produced, that continents are moving and that light travels faster than sound.
The survey's margin of error is plus or minus 3 percentage points.
In its current form, the survey has been given every two years since 1979 and overall the results haven't changed much, Pollak said. The United States did slightly better than 14 other industrialized countries in the early 1990s, ranking about equal to Denmark and the Netherlands, Pollak said. A quick look at new survey data suggests this country is still somewhat ahead, she said.
Some see reason for hope in survey results over the years. Jon Miller of Northwestern University, who directed the survey from 1979 to '99, has his own index of scientific literacy. It includes an understanding of scientific process plus vocabulary.
By that gauge, "the trend in the last decade has been very encouraging," he said, with science literacy growing from 10 percent in 1988 to 17 percent in 1999. He hasn't calculated the number for the new survey.
Miller, director of the Center for Biomedical Communication at Northwestern's medical school, found in 1997 that Americans scored higher on science literacy than Europeans, the Japanese or Canadians. That's probably unchanged, he said.
What bothers Pollak the most is the finding that only about a third of adults showed a good understanding of the scientific process.
"This is where science can benefit people in their daily lives," Pollak said. People get bombarded with claims by psychics and medical quacks, she said, and if they don't understand about critical thinking and scientific evidence, they can waste time and money.
That understanding also helps citizens confront scientific political issues where the media are often content to present both sides of an argument, no matter which side has better evidence, said Shirley M. Malcom, head of education for the American Association for the Advancement of Science.
Moreover, experts say, with the spread of technology, workers will have to be able to use it and the critical-thinking and problem-solving skills that should be learned in science classes.
There's another, related concern. How will the United States supply qualified workers for careers in science and technology? Nowadays, the nation leans heavily on foreign help.
At Human Genome Sciences Inc. of Rockville, Md., only about half the workers with the highest levels of technical skill were U.S.-born, estimates chief executive officer William Haseltine.
In fact, about 10 percent of the American work force in biotechnology — including drug companies — are foreign nationals who hold an "H-1B" visa that lets them work here temporarily, said Steve Dahms, who chairs the work-force committee of the U.S. Council of Biotechnology Centers.
The science foundation reports that as of 1999, about a quarter of all U.S. workers holding a doctorate in science or engineering were foreign-born. For computer science and engineering doctorates, about 45 percent were foreign-born, and for biological sciences, 27 percent.
We've already seen some reverse brain drain, back to China, back to Europe, back to Germany in particular," by people who've gotten years of training in the United States, Haseltine says.
The obvious response, Haseltine and others say, is to produce more Americans with science and engineering expertise.
So, if it's up to this country, how does it increase Americans' understanding of science? The real engine, experts say, is the schoolroom.
It has to start early. Around fourth or fifth grade, "you go into the valley of the shadow," where pupils turn off to science and math unless they've experienced good classroom material, chances to explore the topic and "teachers who love the subject," said Judith Ramaley, with the science foundation's education and human resources section.
The foundation plans to spend about $1 billion over the next five years to improve science and math teaching, Ramaley said.
Among its priorities is better training in those subjects for teachers.
Currently, many who teach math or science don't have backgrounds in those subjects, she said. The science foundation reported in 2000 that 31 percent of math teachers and 20 percent of science teachers in grades 7-12 lack a major or minor in their subjects.
But better training before teaching doesn't solve another problem. Within five years of starting a teaching career, nearly half of urban math and science teachers leave the classroom, said Harold Pratt, immediate past president of the National Science Teachers Association. They'd stick around more if they had inducements like more mentoring, better teaching assignments and chances to take classes and seminars, he said.
Ramaley emphasized that teachers also need to be paid more and "treated as professionals" with more say in what and how they teach.
Another priority among experts is good classroom materials — not just textbooks, but kits and other ways of teaching the big ideas in math and science, Ramaley said. Malcom, of the AAAS, says it's also important to get colleges to convince their students that math and science are important parts of a well-rounded education.
"I would be ashamed if I didn't know anything about literature or political science, or psychology or things like this, as a person who's supposedly liberally educated," she said. "And yet others think nothing about saying, 'I don't know anything about science and mathematics.' "