U.S. grasp of science is improving — but there’s a catch

How adults answer science questions can depend on test’s wording


People in the U.S. are more likely to demonstrate knowledge about evolution if they’re asked about elephants, not people.

NikSimpson (CC-BY-SA-4.0)

WASHINGTON, D.C. — Students are used to taking science tests in school. Every two years the National Science Foundation and other agencies also test a cross-section of American adults on science. And their latest scores have just come out. They show those adults generally get a passing grade. Not a great grade, mind you. It appears some adults still have a lot to learn.

Basically, the test is “a little quiz on what people know about science issues,” explains Peter Muhlberger. He’s a political scientist and analyst at the National Center for Science and Engineering Statistics (NCSES) in Arlington, Va.

The test makes 11 statements. People are to mark them as true or false. One example: “Electrons are smaller than atoms.” (That’s true.) Or, “Antibiotics kill viruses as well as bacteria.” (No — they only kill bacteria.)

The results give an idea about how much U.S. adults know about science. NCSES uses nine of the test questions to track how well people have been doing over time. On average, those who took the latest test got almost 65 percent of the questions right. The good news: That score is somewhat higher than when researchers first began surveying adults on this in the late 1980s.

Progress over the years has been “small but significant,” Muhlberger says. He and other researchers shared the results of that test and other surveys about science and technology here, on February 14, at the annual meeting of the American Association for the Advancement of Science.

People — or elephants?

For nine of the science questions on the test, Americans’ responses were generally consistent with those from people in Europe and some other countries. These included questions such as whether all radioactivity is made by humans, whether the continents have been moving for millions of years, and whether a father’s gene determines a baby’s sex.

But two questions were outliers. In other words, the scores on them stood out as oddities, compared to the rest of the data. These scores were low compared with the other questions. And in comparison to people from other countries, Americans did worse on those two questions than they did on the others.

pew science indicators
This graph shows that the average number of correct responses to nine general science questions has risen slightly over the last two decades. Science & Engineering Indicators/ National Science Foundation et al.
One of these outlier questions asked about the Big Bang — the rapid expansion of dense matter that marked the origin of the universe. The other question asked about evolution. That’s the process by which species change over time. Such changes can lead to new types of organisms that are better adapted to their environment. Both the Big Bang and evolution are well-established and accepted concepts in science. Yet because of their religious or other beliefs, some people reject both concepts.

To learn what people truly know about evolution, the researchers set up an experiment. They gave the science test to two groups of people. One group was asked if it is true or false that people evolved from earlier species of animals. The other group instead was asked if elephants evolved from earlier species of animals. (The correct answer in both cases is “True.”)

Three-fourths of the group asked about elephants got the answer right. That’s about as often as they were right on the other science-knowledge questions. And it is in line with how people in other countries score on the same question. In contrast, only half of the people asked about human evolution got the answer right. That’s consistent with the idea that some people have a particular problem accepting the idea of human evolution.

Muhlberger says the team is considering changing the wording of the question in future tests, leaving out reference to human evolution. “We now have a better way of asking about evolution than we did in the past,” he says.

Lydia Saad says such a change makes sense. She’s a social scientist at the Gallup Organization in Princeton, N.J., and did not work on the general-science test or the question experiment. “It’s not that people don’t understand evolution,” she says. Instead, some people’s religious or other beliefs may pressure them to answer a certain way. And, she says, “that makes it look like they don’t understand science.”

Digging into the data

Researchers dug into the science answers some more. They used statistics, a type of mathematical analyses, to compare two groups of data. They wanted to test if they differed in some important way. And those analyses showed that in general, people who went to college scored higher on the quiz than did those who did not go to college.

Gender also made a difference. Men scored slightly higher overall on the science quiz. They also did slightly better on questions about physical science, which made up more than half of the quiz questions. Women were more likely to get the biology questions right. The reasons for those results are not clear.

The new report doesn’t just look at what people know. It also looks at how people feel about different science-related topics, such as climate change, energy and other issues. Understanding how such attitudes may influence people is important, say the researchers. Much of that analysis was done by the Gallup Organization and the Pew Research Center in Washington, D.C.

Science-related issues are “part and parcel of our civic debate,” says Cary Funk. She’s a social scientist at Pew. “That’s why it’s important to gather data from representative samples of the public, to measure what people think about these issues.”

“We need to know how people think about lots of things,” adds John Besley. He’s a social scientist who studies communications at Michigan State University in East Lansing. After all, he says, “Science is part of society.”

Power Words

(for more about Power Words, click here)

antibiotic   A germ-killing substance prescribed as a medicine (or sometimes as a feed additive to promote the growth of livestock). It does not work against viruses.

atom    The basic unit of a chemical element. Atoms are made up of a dense nucleus that contains positively charged protons and neutrally charged neutrons. The nucleus is orbited by a cloud of negatively charged electrons.

bacterium    (plural bacteria) A single-celled organism. These dwell nearly everywhere on Earth, from the bottom of the sea to inside animals.

Big Bang    The rapid expansion of dense matter that, according to current theory, marked the origin of the universe. It is supported by physics’ current understanding of the composition and structure of the universe.

biology    The study of living things. The scientists who study them are known as biologists.

civic    An adjective that refers to things relating to cities and towns or the duties and activities of people in them.

climate change   Long-term, significant change in the climate of Earth. It can happen naturally or in response to human activities, including the burning of fossil fuels and clearing of forests.

continent   (in geology) The huge land masses that sit upon tectonic plates. In modern times, there are six geologic continents: North America, South America, Eurasia, Africa, Australia and Antarctica.

correlation   A mutual relationship or connection between two variables. When there is a positive correlation, an increase in one variable is associated with an increase in the other. (For instance, scientists might correlate an increase in time spent watching TV with an increase in risk of obesity.) Where there is an inverse correlation, an increase in one value is associated with a decrease in the other. (Scientists might correlate an increase in TV watching with a decrease in time spent exercising each week.) A correlation between two variables does not necessarily mean one is causing the other.

data    Facts and statistics collected together for analysis but not necessarily organized in a way that give them meaning. For digital information (the type stored by computers), those data typically are numbers stored in a binary code, portrayed as strings of zeros and ones.

electron    A negatively charged particle, usually found orbiting the outer regions of an atom; also, the carrier of electricity within solids.

evolution   A process by which species undergo changes over time, usually through genetic variation and natural selection. These changes usually result in a new type of organism better suited for its environment than the earlier type. The newer type is not necessarily more “advanced,” just better adapted to the conditions in which it developed.

gender   The attitudes, feelings, and behaviors that a given culture associates with a person’s biological sex. Behavior that is compatible with cultural expectations is referred to as being the norm. Behaviors that are incompatible with these expectations are described as non-conforming.

gene   (adj. genetic) A segment of DNA that codes, or holds instructions, for producing a protein. Offspring inherit genes from their parents. Genes influence how an organism looks and behaves.

National Science Foundation    The U.S. Congress created this independent federal agency in 1950 to promote the advancement of science; national health, prosperity and welfare; and the nation’s defense. This agency funds nearly one-fourth of all federally supported basic research in U.S. colleges and universities. In many fields such as mathematics, computer science and the social sciences, NSF is the major source of federal funding.

outlier   (in statistics) An observation that lies outside the range of the rest of the data.    

physical science   Fields of science (such as chemistry, physics and materials science) that deal with laws of nature and the physical attributes of systems, such as color, temperatures, winds, electricity, magnetism, speeds, energy, mass, chemical reactions, changes of state (such as solids turning into liquids or gases), and forces (such as gravity).

radioactive    An adjective that describes unstable elements, such as certain forms (isotopes) of uranium and plutonium. Such elements are said to be unstable because their nucleus sheds energy that is carried away by photons and/or and often one or more subatomic particles. This emission of energy is by a process known as radioactive decay.

social science   The scientific study of people and their relationships to each other. People who work in this field are known as social scientists.

society   An integrated group of people or animals that generally cooperate and support one another for the greater good of them all.

statistics    The practice or science of collecting and analyzing numerical data in large quantities and interpreting their meaning. Much of this work involves reducing errors that might be attributable to random variation. A professional who works in this field is called a statistician.

survey    (in statistics) A questionnaire that samples the opinions, practices (such as dining or sleeping habits), knowledge or skills of a broad range of people. Researchers select the number and types of people questioned in hopes that the answers these individuals give will be representative of others who are their age, belong to the same ethnic group or live in the same region.

universe   The entire cosmos: All things that exist throughout space and time. It has been expanding since its formation during an event known as the Big Bang, some 13.8 billion years ago (give or take a few hundred million years).

virus   Tiny infectious particles consisting of RNA or DNA surrounded by protein. Viruses can reproduce only by injecting their genetic material into the cells of living creatures. Although scientists frequently refer to viruses as live or dead, in fact no virus is truly alive. It doesn’t eat like animals do, or make its own food the way plants do. It must hijack the cellular machinery of a living cell in order to survive.

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