Understanding Gallup’s Latest Poll on Evolution

Glenn Branch

When a pollster that’s been surveying public opinion about evolution at intervals over the past thirty-five years declares, “In US, Belief in Creationist View of Humans at New Low,” as Gallup did on May 22, 2017, it’s a good idea to pay attention. But it’s also a good idea to pay attention to the details.

Since 1982, Gallup has been asking “Which of the following statements comes closest to your views on the origin and development of human beings?” and presenting respondents with three options (not always in the same order, to control for order effects):

  • God created human beings pretty much in their present form at one time within the last 10,000 years or so;
  • Human beings developed over millions of years from less advanced forms of life, but God guided this process;
  • Human beings have developed over millions of years from less advanced forms of life, but God had no part in this process. (emphasis in original)

For brevity and consistency with the terminology in Gallup’s latest report, let’s call the views expressed by these statements the “creationist view,” the “guided evolution view,” and the “secular view,” respectively.

The Headlines

The big news, as advertised by Gallup’s headline, is that the level of support for the creationist view is at a new low. Indeed, in 1982, 44 percent of respondents favored the creationist view. Never quite breaking the 50 percent mark, the level of support didn’t dip below the 1982 level until 2017, when it reached only 38 percent.

As a result of the fall in support of the creationist view, the guided evolution view is now equally popular, with a 38 percent level of support. That was the same level of support it enjoyed in 1982, although it rose as high as 40 percent and sunk as low as 32 percent in the intervening years.

The level of support of the secular view is now at 19 percent. That represents a substantial increase, for it began at 9 percent in 1982 and remained relatively flat from then until the turn of the century. But it more than doubled between 1999 and 2014, when it first reached the 19 percent level.

There are limits, of course, to what can be inferred from public opinion poll data in general. But there are features of Gallup’s question in particular that make understanding the results less than straightforward—one inherent in the options offered to respondents and one resulting from the options not offered.

Examining the Options

The creationist option in Gallup’s question is designed to appeal to creationists in general, not only to young-Earth creationists of the Ken Ham variety. Certainly young-Earth creationists would agree that humans were created by God within the last 10,000 years or so—because of course they think that everything was.

But while old-Earth creationists don’t think that everything was created by God within the last 10,000 years or so, they generally agree that humans were created by God within the last 50,000 years or so. (Hugh Ross’s Reasons to Believe ministry seems recently to have extended the outmost bound to 150,000 years ago.)

It seems likely that old-Earth creationists would tend to accept the creationist view—perhaps grudgingly—rather than endorse the common descent of humans and the rest of life. It is harder for creationists to reconcile common descent than the antiquity of the universe with their interpretation of the Bible.

The secular option in Gallup’s question, in contrast, is probably not designed to appeal only to atheists and agnostics. But its wording—emphasizing, in a way that may appear dogmatic, God’s playing no part in evolution—may deter respondents of faith from accepting it, even if they have no quarrel with any of the science.

As a result, the guided evolution option is likely to attract respondents who, on the one hand, accept common descent and, on the other hand, believe in God—a category so heterogeneous that it includes both Michael Behe and Kenneth R. Miller, who testified on opposite sides in the Kitzmiller v. Dover “intelligent design” trial in 2005.

Uncertainty and Ambivalence

It would be a mistake to think that Gallup’s respondents are firmly committed to, and wholly sure of, their responses. Answers that don’t match the three options and refusals to answer are recorded as “Other/No opinion” (5 percent in 2017), but they are not explicitly invited. That demonstrably makes a big difference.

In 2009, George F. Bishop and his colleagues conducted a survey using a modified version of the Gallup question, which added two more options to capture ambivalence and uncertainty:

  • None of these come close to my beliefs;
  • Not at all sure which is true.

They found that the new options attracted almost a quarter of respondents: 10 percent of respondents were ambivalent—not regarding any of the standard Gallup choices as appealing—and 14 percent were uncertain.

The presence of the two extra options reduced the level of support of the creationist view (35 percent, compared to 44 percent in the 2008 Gallup poll) and of the guided evolution view (26 percent, as compared to 36 percent), but not of the secular view (16 percent, as compared to 14 percent).

Applying a proportionate adjustment to the 2017 data from Gallup would result in 29 percent support of the creationist view, 27 percent support of the guided evolution view, and 21 percent support of the secular view. There would no longer be a majority explicitly accepting common descent, although at 48 percent it would be close.

The Take-Home Message

So it seems, on the one hand, that the conceptual geography of the creationism/evolution controversy is more complicated than Gallup’s question acknowledges, and, on the other hand, that the public’s engagement with the controversy is less intensive than Gallup’s question presupposes.

This is not to criticize Gallup, which deserves credit, especially for its persistence in asking the same question for thirty-five years. But it is a reminder that poll results must be interpreted with care, to compare them with the results from different polls, and above all to look at trends rather than at individual polls.

While creationism may be at a new low as measured by Gallup’s question, it is important to remember that it remains alive and well, inspiring constant attacks on the teaching of evolution in statehouses, courthouses, and classrooms across the country. There is certainly no cause for complacency.

 


 

Further Reading

  • Berkman, Michael, and Eric Plutzer. 2010. Evolution, Creationism, and the Battle to Control America’s Classrooms. Cambridge: Cambridge University Press.
  • Bishop, George F., Randal K. Thomas, and Jason A. Wood. 2010. Measurement error, anomalies, and complexities in Americans’ beliefs about human evolution. Survey Practice 3(1). Available online at http://surveypractice.org/index.php/SurveyPractice/article/view/119/html.
  • Gallup News Service. 2017. Gallup polls social series: Values and beliefs. Gallup. Available online at http://www.gallup.com/file/poll
    /210974/170522Evolution.pdf.
  • Swift, Art. 2017. In US, belief in creationist view of humans at new low. Gallup (May 22). Available online at http://www.gallup.com/poll/210956/belief-creationist-view-humans-new-low.aspx.

Glenn Branch

Glenn Branch is deputy director of the National Center for Science Education, a nonprofit organization that defends the teaching of evolution and climate science. He is the coeditor, with Eugenie C. Scott, of Not in Our Classrooms: Why Intelligent Design is Wrong for Our Schools (Beacon Press, 2006).


When a pollster that’s been surveying public opinion about evolution at intervals over the past thirty-five years declares, “In US, Belief in Creationist View of Humans at New Low,” as Gallup did on May 22, 2017, it’s a good idea to pay attention. But it’s also a good idea to pay attention to the details. …

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