A survey by the Oklahoma State University Department of Agricultural Economics finds that over 80 percent of Americans support “mandatory labels on foods containing DNA,” about the same number as support mandatory labeling of GMO foods “produced with genetic engineering.” Oklahoma State economist Jayson Lusk has some additional details on the survey.

If the government does impose mandatory labeling on foods containing DNA, perhaps the label might look something like this:

WARNING: This product contains deoxyribonucleic acid (DNA). The Surgeon General has determined that DNA is linked to a variety of diseases in both animals and humans. In some configurations, it is a risk factor for cancer and heart disease. Pregnant women are at very high risk of passing on DNA to their children.

The Oklahoma State survey result is probably an example of the intersection between scientific ignorance and political ignorance, both of which are widespread. The most obvious explanation for the data is that most of these people don’t really understand what DNA is and don’t realize that it is contained in almost all food.

When they read that a strange substance called “DNA” might be included in their food, they might suspect that this is some dangerous chemical inserted by greedy corporations for their own nefarious purposes.

Polls repeatedly show that much of the public is often ignorant of both basic scientific facts, and basic facts about government and public policy. Just before the 2014 elections, which determined control of Congress, only 38 percent realized that the Republicans controlled the House of Representatives before the election, and the same number knew that the Democrats control the Senate.

The public’s scientific knowledge isn’t much better. A 2012 National Science Foundation survey even found that about 25% of Americans don’t know that the Earth revolves around the sun, rather than vice versa. Issues like food labeling bring together political and scientific knowledge, and it is not surprising that public opinion on these subjects is very poorly informed.

It would be a mistake to assume that widespread political and scientific ignorance are the result of “the stupidity of the American voter,” as Obamacare architect Jonathan Gruber put it. Political ignorance is not primarily the result of stupidity. For most people, it is a rational reaction to the enormous size and complexity of government and the reality that the chance that their vote will have an impact on electoral outcomes is extremely low.

The same is true of much scientific ignorance. For many people, there is little benefit to understanding much about genetics or DNA. Most Americans can even go about their daily business perfectly well without knowing that the Earth revolves around the sun. Even the smartest people are inevitably ignorant of the vast majority of information out there. We all have to focus our time and energy on learning that information which is most likely to be instrumentally useful, or at least provide entertainment value. For large numbers of people, much basic political and scientific information doesn’t make the cut.

Unfortunately, this is a case where individually rational behavior leads to potentially dangerous collective outcomes. While it doesn’t much matter whether any individual voter is ignorant about science or public policy, when a majority (or even a large minority) of the electorate is ignorant in these ways, it can lead to the adoption of dangerous and counterproductive government policies. In this case, excessive and unnecessary warning labels on food products could confuse consumers and divert their limited attention from real dangers.

Although Jonathan Gruber was wrong to believe that American voters are necessarily stupid, he was right about the pervasiveness of public ignorance — and the dangers it poses.

This post first appeared at the Volokh Conspiracy in 2015.