Among biologists, evolution as the explanation for the diversity of life is nearly universally accepted. But for 4 in 10 Americans, creationism is an easier pill to swallow.
Now, a study has found understanding the nature of science is the number one greatest predictor of evolution acceptance in college students. The research is important because it provides much-needed guidance to educators on how they can improve science literacy in the next generation.
"Asking why it is critical that students accept evolution is almost like asking why it is critical that students understand biology," said lead author Ryan Dunk, a biology Ph.D. candidate in the College of Arts and Sciences.
Evolution helps us understand a whole score of important scientific issues, he argues, like human disease and the impacts of climate change.
But no matter how many educational reforms, the percent of Americans who accept evolution has remained relatively unchanged for the past 35 years. Right now, only 33 percent of Americans believe evolution has occurred due to natural processes, according to a Pew Research study.
So what are we doing wrong?
To find out, a questionnaire that measures the acceptance of evolution was given to anatomy and physiology students at the University of Wisconsin-Milwaukee (UWM). The data was then used to quantitatively model what factors influence an individual's acceptance or rejection of evolution.
The study is a first. Instead of just looking at one single trait, Dunk and his team applied a more comprehensive approach. They combined all of the factors to find out which are more important relative to each other.
The factors in question include things like knowledge of evolution, religiosity, an understanding of the nature of science, and something called epistemological sophistication – which is all about understanding the nature of knowledge.
"We were able to look at interactions that are actually going on in people—every individual has a level of knowledge of evolution, a level of their knowledge of nature of science, a level of religiosity, and so on," said Dunk.
Of all the variables, the findings reveal an understanding of the nature of science, predicts acceptance of evolution most. This understanding includes recognizing the questions science can and cannot answer, and the application of the scientific method.
As far as the other factors go, an understanding of science was followed by (in descending order) religiosity, openness to experience, religious denomination, number of biology courses previously taken, and knowledge of evolutionary biology terms.
Contrary to conventional wisdom, the results support a growing body of evidence that suggests acceptance of evolution is less influenced by knowledge of evolutionary facts and more influenced by a general understanding of the aims and process of science.
"We know we don't just need to teach them the facts better, because we have been working on evolution curriculum reforms for decades that have moved the needle very little on wide-scale acceptance," said Dunk.
The authors suggest if teachers spend more time on the nature of science, they can help raise the acceptance of evolution, and maybe even squash other forms of science denial while they are at it - killing two birds with one stone.
Surprisingly, the authors don't see religion as a hindrance to greater evolution acceptance. Co-author Jason Wiles says in previous studies he has conducted, acceptance of evolution did not come at the expense of religious activity, or vice versa.
"It may be that as students learn more about how science works, they rely more on scientific explanations for natural phenomena, but that doesn't mean they must abandon religion in the process," said Wiles, a Syracuse associate professor of biology.
Dunk and Wiles plan to continue exploring evolution acceptance, but this time they are going to do a longitudinal study across undergraduate students.
"All the people we survey are currently students. But they're going to be educated members of the general public," Dunk said.
"Our work aims to help them have an appreciation for scientific inquiry and nature itself."
The study was published in the open-access journal Evolution: Education & Outreach.