Public (mis)understanding of science

The National Science Board has published the results of its latest report on the state of the art in science and engineering. The report includes, as it always does, a set of survey questions about common scientific facts, and a detailed breakdown of how well the public did. It's an interesting snapshot, especially when you compare it to previous years, which go back to 1988. The report is produced every two years by the U.S. National Science Foundation.

You may read various summaries of the report in the news, which will likely say that the public is still relatively uniformed about science, but that we're doing about as well as European countries on most questions except evolution, where we are abysmally bad. I thought it would be interesting to dig into the reports Appendices and look at some specific survey questions.

1. Evolution. The precise question asked was this: "Human beings, as we know them today, developed from earlier species of animals (true or false)." This is the one that gets the most attention, so I have to include it. 43% of the U.S. public got this one right, a number that has hardly budged in 20 years - the number was 45% in 1985. Note that because this is a true/false question, the fact that only 43% gave the correct answer ("true") means that we did worse than random guessing. Evidently the average person misses this one not because he/she is guessing, but because he/she is confident in the wrong answer. Rather sad but not surprising on this one. We have a lot of work yet to do to counteract the creationists.

2. "Does the Earth go around the Sun, or the does the Sun go around the Earth?" For this question, 76% of people answered correctly, a number that is very slightly better than the average of 72-73% in most years. But this is still a terrible result, because again we have a true/false question. A simple bit of statistics tells us that fewer than 76% of the public actually knows the answer: if 50% of people know the answer for certain, and the remaining 50% just guess, then the latter group will still get the right answer half the time. This means we'll observe 75% correct answers, which is basically what the survey found. So only 50% of the public knows that the earth goes around the sun. And the survey included a followup question: "How long does it take for the Earth to go around the Sun?" Only 55% correctly answered "one year." (How long do the other 45% think it takes?) As a scientist, I can't accept that our public is scientifically literate until they get 100% on this one, so we have a really long way to go.

3. There is some good news in the survey: we seem to be slowly educating the public about the overuse of antibiotics. Here's the survey question: "Antibiotics kill viruses as well as bacteria (true or false)." In 1988, only 26% correctly said false to this one, which shows that the public was seriously misinformed. (Again, mere guessing would get 50% correct, so we can infer that the true "correct" rate of those who really knew the answer was even lower.) In the current survey, this number has risen to 56%, and it's one of the few questions where we see steady improvements over the years. 56% is still just a bit better than guessing, but it is far better than it was 20 years ago. We need to keep spreading the message that viruses are not affected by antibiotics (stop taking antibiotics when you have a cold!), because this one seems to be working. I'll hazard a guess that one reason we're seeing improvement here is that doctors are helping to spread the word among their patients.

4. "Electrons are smaller than atoms." Only 53% got this true/false question right (it’s true! of course) and that’s an improvement over 45% in the previous survey in 2004. I'm not sure what people think electrons are, but I guess most of them don't exactly know.

The rest of the results can be found in the National Science Board report’s appendices – I’ll put the actual 12 questions at the bottom of this entry. In another very interesting survey, they tested people’s understanding of scientific experiments with the following scenario and question:

(1) Two scientists want to know if a certain drug is effective against high blood pressure. The first scientist wants to give the drug to 1,000 people with high blood pressure and see how many of them experience lower blood pressure levels. The second scientist wants to give the drug to 500 people with high blood pressure and not give the drug to another 500 people with high blood pressure, and see how many in both groups experience lower blood pressure levels. Which is the better way to test this drug? and (2) Why is it better to test the drug this way?

The correct answer, of course, is that the second scientist has a better design, for multiple reasons, including the placebo effect and natural variation in blood pressure. Only 42% of respondents got this correct, but that is quite a bit higher than 1995 (the first year they asked this question), when only 26% got it. So perhaps we are slowly making progress in educating the public about the scientific method. But 42% is still an F in my classes!

Overall, it appears public understanding is improving very slightly in a few areas, and not budging in others. (And it decreased on one question, about the Big Bang.) This does not bode well for the progress of our society, but we have to keep trying: as scientists, we need to educate the public at every opportunity. Most scientific concepts are not controversial, and an appreciation for science by the public might put pressure on politicians to use good science (rather than distorting or ignoring it) in decisions affecting all of us. One strategy that might help is to explain that it's in everyone's self-interest to understand basic scientific methods, so you won't be fooled by politicians, special interest groups, or quacks offering bogus medical treatments who are only too happy to distort science to support their own agenda.

The Questions (and answers)

The center of the Earth is very hot. (True)
All radioactivity is man-made. (False)
Lasers work by focusing sound waves. (False)
Electrons are smaller than atoms. (True)
The universe began with a huge explosion. (True)
The continents on which we live have been moving their location for millions of years
and will continue to move in the future. (True)
Does the Earth go around the Sun, or does the Sun go around the Earth?
(Earth around Sun)
How long does it take for the Earth to go around the Sun? (One year)
It is the father’s gene that decides whether the baby is a boy or a girl. (True)
Antibiotics kill viruses as well as bacteria. (False)
Human beings, as we know them today, developed from earlier species
of animals. (True)