NAGT > Publications > In the Trenches > In the Trenches - April 2017 > Seven Ways to Teach Controversial Issues

Seven Ways to Teach Controversial Issues

STEVEN NEWTON ( is programs and policy director at the National Center for Science Education and a professor of geology at the College of Marin, Kentfield, California.

"I wrote what you expected, but I want to let you know that I don't believe in plate tectonics."

The quotation above is the curious statement that greeted me at the end of a final exam in one of my introductory geology classes. One might presume that such a student bombed the test, but the truth is this student wrote an exemplary, fact-rich final exam essay on plate tectonics, earning full marks and an A in the course. I was nevertheless left with a sense of deep unease and this question: How could someone who knew the facts so well reject the existence of plate tectonics?

We geoscience teachers may have more of these students than we realize. One in five Americans thinks the Sun orbits the Earth (Crabtree, 1999). Sixty-three percent of Americans cannot name the planet closest to the Sun, yet sixty percent know the name of Superman's home planet ("New national poll," 2006). Fortyone percent think dinosaurs and humans lived together at the same time (Mack, 2015). Fifty-four percent think electrons are bigger than atoms (Pew Research Center, 2009). We can teach about rock-forming silicate minerals until we're blue in the face, but many students still believe crystals contain "healing energy." Our science students reflect the alienation from science characteristic of so many in our country.

What can you, as a K-12 teacher or college professor, do to help students learn how to tell reliable sources from propaganda and evaluate evidence for themselves? A lot, it turns out.

At the National Center for Science Education, we have decades of experience assisting teachers, parents, and students facing misrepresentations of science in the public school classroom. Most of NCSE's work has involved keeping creationism out of the classroom STEVEN NEWTON ( is programs and policy director at the National Center for Science Education and a professor of geology at the College of Marin, Kentfield, California. and making sure that evolution is taught without equivocation. In recent years, as we observed the same kinds of problems emerging in the Earth sciences, we added climate change to our lineup. From these decades of work, we can distill a number of ideas to help you, as a teacher, effectively teach scientific topics that are socially, but not scientifically, controversial:

1. Show, Don't Tell

Many students come to class having been told that evolution is a plot to undermine religion and climate change is a nefarious hoax devised to sabotage the economy. Teachers face built-in resistance when announcing lessons on evolution or climate change.

One way we have found effective to counter this is to teach these topics backwards. Instead of beginning with the conclusions—"evolution happens"—start with basic, non-controversial observations: individuals vary, part of that variation is genetically inherited from parents, gene frequencies in populations change over time. These observations will lead students to understand how evolution happens, so that by the time teachers call it evolution, students already have good reasons to accept it.

For climate change, teachers could start with Tyndall's 1859 observation that a clear gas, CO2, absorbed infrared radiation surprisingly well, followed by Arrenhius' 1896 investigations into the idea that anthropogenic CO2 emissions could affect global temperatures. Show students the data: show them how CO2 has varied over time, emphasizing the rise following the Industrial Revolution.

If you show students the evidence and have them come to the conclusion themselves, rather than simply being told "this is the way it is," students will be far less resistant to ideas.

2. Respect Students

It may be tempting to respond to student challenges about evolution or climate change with firm rebukes. A popular YouTube video (Creationist student owned by Dr. Tim White) shows just such an exchange between a naive student and a world famous paleoanthropologist. But if one's goal is to spark curiosity and open minds, responding to your students in a confrontational way will probably be counterproductive.

Scientists are trained in an environment of relentless peer criticism, but for many non-scientists robust challenges come across as needlessly aggressive. If students feel you are disrespecting them as people, it becomes less likely they'll be open to what you have to say.

When I discuss evolution and the fossil record, I have been challenged many times in the classroom by students who often repeat hackneyed creationist talking points. My response is never to ridicule the student, but rather to smile and help them, and the entire class, see the flaws. When students say that random mutations cannot produce new genetic "information," I focus on their word "information," probing what they think that overly broad term means in this context, challenging them to come up with examples of things are not information. Then we examine their false usage of "random." My goal is to show them where their thinking has gone wrong, not to attack them for parroting what an authority figure has told them.

State and local standards spell out with some specificity what to teach in the [K-12] classroom...

If a principal tells you, as a teacher, that you must "balance" evolution by bringing in creationist materials to a science lesson, a good response for you is to ask where these appear in the standards.

Respect students as people, and you might have a chance of opening their minds a little bit.

3. Use the Standards

If one is a K-12 teacher, then state and local standards spell out with some specificity what to teach in the classroom. In the college classroom, instructors have much more latitude, but every course still has a course syllabus and objectives spelling out the expectations of what will be covered.

If a principal tells you, as a teacher, that you must "balance" evolution by bringing in creationist materials to a science lesson, a good response for you is to ask where these appear in the standards. If a parent complains that your section on climate change doesn't show "the other side," point to the science standards as a place that prescribes covering only the real science.

4. Don't Debate the Science

One common tactic of science denialists is to ask that students hold mock debates. In other areas of education, debates do have pedagogical merit; when students research an assigned viewpoint that may not correspond to their own and then argue that viewpoint, they can gain valuable skills. However, there is a danger here in debates when they veer to long-settled questions such as "Is evolution real?" or "Is climate change happening?" It is misleading even to suggest that there are two scientifically valid sides to debate. Students researching the opposing views will find plentiful, non-scientific materials from creationists and climate change deniers that are carefully designed to mimic credible scientific publications but in fact based on neither peer-review nor approved curricula and standards. Introducing such materials to the class will severely confuse all students about these issues.

Public school classrooms are not the place for students encountering these topics for perhaps the first time to be asked to discriminate between non-scientific sources and scientific conclusions established through decades of research by thousands of scientists, publishing tens of thousands of peer-reviewed research articles.

We don't ask math students to weigh in with their opinions about the quadratic equation. We don't encourage history students to evaluate if we landed on the moon. You should not suggest, even indirectly, to your students that some areas of science, namely evolution and climate change, are debatable.

5. Reject False Choices

Creationists frequently propose a false choice: If you accept evolution, then you must reject God. When phrased this way, students of faith will think they have few options but to reject the science. Climate change deniers also utilize false, simplistic choices: If you want to save the environment, that means you have to give up owning a car. If you accept climate change, the government will regulate every aspect of your life.

These false, hyperbolic statements are meant to instill fear as a way to misdirect students from the weaknesses of their positions. Creationists and climate change deniers cannot argue from data or logic; their last, sad contrivance is distraction.

If you find students engaging in this kind of false dichotomy, break the cycle for them by helping them see the world as more complex. Many people of faith also accept the scientific reality of evolution; in fact, prominent biologists such as Ken Miller and Francis Collins are religious. Accepting the reality of climate change does not mean giving up cars or jobs or personal freedom; your students might learn this as they drive to work in their electric vehicles to their jobs installing solar panels.

6. Emphasize Process of Science

The way we teach science often conveys the false impression to students that science is a list of facts to be memorized; memorize the Krebs cycle, we imply, and then you're a biologist. Most teachers don't really mean to teach science this way, but the overbearing demands of an over-stuffed curriculum leave little time for the far more effective Socratic methods that would walk students through the way scientists think. Harried teachers naturally fall back on teaching topics in a way that can be easily assessed—the memorization of facts.

But science is not individual facts, but rather the investigative process by which those facts come to be known. Emphasizing process over conclusions will help in teaching socially-controversial topics. Using examples from the history of science, you can show that science is dynamic and responds to new data. Challenge stubborn students to find data themselves, but help them see that the process of discovering new data has restrictions and requirements. Their opinions don't count; precipitates in test tubes do.

7. Beware the "Backfire Effect"

Nyhan and Reifler (2010) demonstrated a counterintuitive phenomenon in which subjects resisted information correcting their misperceptions. In essence, if someone latches on to an incorrect idea, and you present them with the real data, that person will cling on to their incorrect idea more fiercely. Nyhan and Reifler termed this the "backfire effect."

This "backfire effect" has implications for the limits of science education. If students come into a classroom already convinced that evolution is not real or that climate change is a hoax, then as information is presented that contradicts their opinion, they will tend to cling to that opinion even stronger than before. You can give them article after article, video after video, and their false convictions become more deeply cemented.

There is no magic bullet for science teachers to overcome this effect. What these findings do, then, is to underscore the importance of reaching children early with the facts of real science. Evolutionary concepts should be introduced as soon as children investigate animals, not left for a late chapter in high school biology at the end of the semester. The reality of climate change can be gradually introduced every time children learn about something in nature – because virtually everything in nature will be affected by climate change.

The "backfire effect" also emphasizes the importance of teachers being well-trained in their disciplines. A stray incorrect comment from a teacher, a misunderstood idea taught hesitantly, and students may cling to a false notion for the rest of their lives, in the face of all attempts to correct their misconception. Every time you walk into a classroom, you have power to influence minds. Make sure to teach only the best science – especially when the topic is socially controversial.


Crabtree, S., 1999 July 6, New poll gauges Americans' general knowledge levels: Gallup,

Mack, E., 2015 June 26, Flintstone facts? 41 percent of Americans say people and dinosaurs co-existed: Cnet,

New national poll finds: More Americans know Snow White's dwarfs than Supreme Court judges, Homer Simpson than Homer's Odyssey, and Harry Potter than Tony Blair, 2006 Aug 14, Business Wire,

Nyhan, B., and Reifler, J., 2010, When corrections fail: The persistence of political misperceptions: Political Behavior, v. 32(2), p. 303-330.

Pew Research Center, 2009 July 9, Public praises science; scientists fault public, media: Pew Research Center for the People and the Press,

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