The level of public acceptance of evolution in the United States is now solidly above the halfway mark, according to a new study based on a series of national public opinion surveys conducted over the past thirty-five years. “From 1985 to 2010, there was a statistical dead heat between acceptance and rejection of evolution,” commented lead researcher Jon D. Miller of the Institute for Social Research at the University of Michigan. “But acceptance then surged, becoming the majority position in 2016.”

In these surveys, American adults in representative national samples were asked whether they accepted, rejected, or didn’t know (or weren’t sure) about the statement “Human beings, as we know them today, developed from earlier species of animals.” From 1985 to 2007, the respondents were in effect evenly divided between acceptance and rejection of evolution. Although acceptance enjoyed a slight lead for all these years except 1985, its lead was not statistically significant except in 1999.

From 2012 to 2020, however, acceptance of evolution was consistently, and statistically significantly, in the lead—and over the past five years, in the majority. In 2020, the most recent year of data available, 52 percent of respondents accepted evolution while only 36 percent rejected it. The scientific community’s level of acceptance of evolution is upward of 98 percent, according to a 2015 survey by the Pew Research Center, so there remains a substantial discrepancy—but the progress is nevertheless encouraging.

What factors are responsible for the increase in the acceptance of evolution? In their study, Miller and his collaborators identified aspects of education—taking college courses in science, having a college degree, and possessing civic science literacy—as the strongest factors promoting the acceptance of evolution. Improvements with regard to these factors—the proportion of Americans with a college degree almost doubled between 1988 and 2018, for example—thus result in improvements in the acceptance of evolution.

A particularly important route for such improvement is through the preparation of public school teachers. A pair of recent studies by researchers at the National Center for Science Education and Pennsylvania State University found, in analyzing data from a nationally representative survey conducted in 2019, that high school biology teachers and middle school science teachers were both more likely to teach evolution as a matter of scientific consensus if they had studied evolution at the college level.

The strongest factor obstructing the acceptance of evolution, according to Miller and his collaborators, is religious fundamentalism, unsurprisingly. For the purposes of the study, religious fundamentalism was measured in terms of belief in a personal god who hears prayers, acceptance of a literal reading of the Bible, self-reported frequency of attendance of religious services during a typical week, self-reported frequency of prayer during a typical week, and agreement with the statement “We depend too much on science and not enough on faith.”

In 2019, only 32 percent of those who scored highest on the scale of religious fundamentalism accepted evolution, as opposed to 54 percent of the whole sample and 91 percent of those who scored lowest on the scale. But even those who scored highest on the scale of religious fundamentalism are showing a shift toward acceptance of evolution. In 1988, a mere 8 percent of religious fundamentalists accepted evolution. While their total numbers declined slightly in the past decade, approximately 30 percent of Americans are religious fundamentalists as defined in the study.

Antievolutionism remains a political force. The Republican Party often panders to religious fundamentalism, and attitudes toward evolution are politicized as a result. Miller and his collaborators found that 34 percent of conservative Republicans accepted evolution in 2019, as compared to 83 percent of liberal Democrats. There is evidence that the politicization is increasing. In 2009, 54 percent of Republicans and 64 percent of Democrats accepted human evolution, but by 2013, the ten-point gap widened to a twenty-four-point gap, according to the Pew Research Center.

Miller and his collaborators concluded their study by expressing a degree of optimism for the future. Between “the continued growth of educational attainment among American adults in the twenty-first century” and “changes in the religious profile of Americans,” such as the increase of nonreligious people and the decrease of inerrantism and related attitudes among religious people, they suggest, “We might expect a moderate rate of growth in the public acceptance of evolution in the United States in the decades ahead.”

The study, “Public Acceptance of Evolution in the United States, 1985–2020,” was published in the journal Public Understanding of Science, a peer-reviewed journal covering all aspects of the interrelationships between science and the public. Besides Miller, the authors are Glenn Branch and Eugenie C. Scott of the National Center for Science Education, Belén Laspra of the University of Oviedo in Spain, Carmelo Polino of the University of Oviedo and Centro REDES in Argentina, and Mark S. Ackerman and Jordan S. Huffaker of the University of Michigan.