Latest science survey is heavy on trivia, light on concepts

The school year may have just started but an early report card is in: Americans got a D in science. Out of 12 multiple-choice questions testing general science knowledge, survey respondents answered eight questions correctly on average, according to a Pew Research Center survey released on September 10. (To see how you measure up before we dive into the answers, take the quiz now.)

The findings might seem worrisome. But a closer look at the results suggests the news isn’t so bad. Some questions tested 3,278 U.S. adults’ grasp of science concepts, but others just tested whether they remember facts. Knowing those answers might get you points in Jeopardy!, but they won’t necessarily help you make better-informed decisions.

The good news: 73 percent of respondents knew the difference between astronomy and astrology (thank our, ahem, lucky stars). Most Americans also knew that the Earth’s hottest layer is its core (86 percent —this question had the most correct responses). And 72 percent knew that a light year is a measure of distance.

A full 74 percent of respondents identified Jonas Salk as the developer of the polio vaccine. Not bad, but I take issue with the question. For one thing, it doesn’t test a concept or implication, such as what vaccines do, how they work, or how many lives they’ve saved. Also, the other choices were all physicists: Marie Curie, Albert Einstein and Isaac Newton. I wonder what the answers would look like if the choices included another scientist known for research related to biology or medicine, such as Louis Pasteur or Rosalind Franklin. The question did reveal a not surprising age bias in historical knowledge: 86 percent of those 65 or older got this right; only 68 percent of those ages 18-29 did. (This bias was reversed for a question on what kind of waves are used to make/receive cellphone calls: 57 percent of the 65+ age group got it right; 80 percent of the youngsters did.)

The error rate was mixed on questions that relied on interpreting data or making use of knowledge. While 76 percent knew that the gravitational pull of the moon is primarily responsible for the oceans’ tides, only 34 percent of people knew that water boils at a lower temperature in high altitudes (this question had the least number of correct responses). When asked about a scatterplot graph relating sugar consumption and tooth decay, 63 percent correctly interpreted the data.

Americans do seem to pay attention to current events: They did pretty well on two questions that related to topics much discussed in the media at the time the survey was taken (August 11-September 3, 2014). One asked them to identify a picture of a comet (78 percent answered correctly). The other asked which element is needed for making nuclear energy/weapons (82 percent got uranium right). However, the other choices were nitrogen, sodium chloride, and carbon dioxide, two of which aren’t elements and none of which end in –ium, a major hint.

It’s difficult to make bold statements about what the quiz results mean. Respondents to Pew’s 2013 quiz got an average of nine out of 13 correct. That’s slightly better than this year’s survey, and I would argue those questions better reflect understanding of science concepts (questions included “What is the major concern about overuse of antibiotics?” and “Is the statement: ‘all radioactivity is manmade’ true or false?”). But perhaps equally important as one’s personal scientific literacy is knowing who to trust if you don’t know the facts yourself. I’d love to know the general scientific literacy of our policy-makers and policy-makers-to-be. But figuring that one out will probably be tougher than the Pew quiz.