Every two years, the National Science Foundation releases a report on the state of science in the U.S. and around the world. It includes survey data for how Americans answer basic scientific questions such as "Does the Earth go around the Sun, or does the Sun go around the Earth?" and "True or false: electrons are smaller than atoms." The results of the most recent survey, conducted in 2012 with more than 2,200 adults, have just been released.
Here's a list of the questions in the survey, along with their correct answers. Below each question, you'll see a graph showing the percentage of Americans who gave the correct answer, along with the percentage of people in other regions who answered correctly when asked similar questions.
As you'll see, in the words of the report, "many Americans provide multiple incorrect answers to basic questions about scientific facts." Then again, "residents of other countries, including highly developed ones, appear to perform no better."
A few notes on the survey results. The first is obvious: The survey was a set of short, factual questions that can't possibly provide a comprehensive picture of a country's scientific literacy. Therefore, as the report says, "generalizations about Americans’ knowledge of science should be made cautiously."
That said, we can pull out a few observations. One is that Americans' performance on these surveys hasn't changed much over the past two decades. Since 1992, the average number of questions that Americans have answered correctly on a nine-question survey has ranged from 5.4 to 5.8. With American policy-makers trying to encourage better science and technology education in schools, we'll see if these numbers start to improve in the years ahead.
Another is that there is a gender gap in the survey results. Men tend to score higher on the survey, answering on average 70 percent of factual knowledge questions correctly, compared with 60 percent for women. The gap, though, depends on which type of science the questions are addressing: Men score higher on questions about physical science, while women score just as high as men on questions about biological science.
Finally, the report shows us that for at least some of the questions, Americans may be answering not based on knowledge, but on belief. As shown above, only 48 percent of Americans responded "true" to the statement "Human beings, as we know them today, developed from earlier species of animals." But if the question was reframed slightly, far more people responded with "true." Given the statement "according to the theory of evolution, human beings, as we know them today, developed from earlier species of animals," 72 percent answered "true." (Emphasis mine.) A similar pattern happens with the Big Bang question. When the statement is simply "The universe began with a huge explosion," 39 percent responded "true." When it is "according to astronomers, the universe began with a huge explosion," 60 percent said "true." This seems to indicate that many Americans are familiar with the theories of evolution and the Big Bang; they simply don't believe they're true.