Photos: UMassAmherstTwitterYouTube

AMHERST, Mass. – A disbelief in human evolution was associated with higher levels of prejudice, racist attitudes and support of discriminatory behavior against Blacks, immigrants and the LGBTQ community in the U.S., according to University of Massachusetts Amherst research published in the Journal of Personality and Social Psychology.

Similarly, across the globe – in 19 Eastern European countries, 25 Muslim countries and in Israel – low belief in evolution was linked to higher biases within a person’s group, prejudicial attitudes toward people in different groups and less support for conflict resolution.

The findings supported the hypothesis of lead author Stylianos Syropoulos, a Ph.D. candidate in the War and Peace Lab of senior author Bernhard Leidner, associate professor of social psychology. They collaborated with co-first author Uri Lifshin at Reichman University in Israel and co-authors Jeff Greenberg and Dylan Horner at the University of Arizona in Tucson. The researchers theorized that belief in evolution would tend to increase people’s identification with all humanity, due to the common ancestry, and would lead to less prejudicial attitudes.

“People who perceive themselves as more similar to animals are also people who tend to have more pro-social or positive attitudes toward outgroup members or people from stigmatized and marginalized backgrounds,” Syropoulos explains. “In this investigation, we were interested in examining whether belief in evolution would also act in a similar way, because it would reinforce this belief that we are more similar to animals.”

In eight studies involving different areas of the world, the researchers analyzed data from the American General Social Survey (GSS), the Pew Research Center and three online crowdsourced samples. In testing their hypothesis about the associations of different levels of belief in evolution, they accounted for education, political ideology, religiosity, cultural identity and scientific knowledge.

“We found the same results each time, which is basically that believing in evolution relates to less prejudice, regardless of the group you’re in, and controlling for all of these alternative explanations,” Syropoulos says.

For example, religious beliefs, like political ideology, were measured separately from a belief or disbelief in evolution, the researchers note. “Regardless of whether one considers religion an important part of their life, belief in evolution relates to less prejudice independently from belief, or lack thereof, in God or any particular religion,” Syropoulos says.

Leidner adds, “This whole effect and pattern seems to be present in all major political systems. It’s very much a human phenomenon, no matter where you are in the world.”

The researchers note that Darwin’s 19th century theory of evolution has been cited to perpetrate racism, prejudice and homophobia, in part through the phrase, “survival of the fittest,” used to describe the process of natural selection.

“There have been theoretical accounts that predict the opposite of what we found, so it was exciting for us to show that this actually is not the case, that the opposite is true and that belief in evolution seems to have pretty positive effects,” Leidner says.

The U.S.-based study involved data from 1993, 1994, 2000, 2006, 2008, 2010, 2012, 2014, 2016 and 2018 – the years the GSS surveyed Americans about their beliefs in evolution, as well as measures of attitudes toward immigrants, Blacks, affirmative action, LGBTQ people and other social matters.

The data analysis showed unfailingly “that the disbelief in human evolution is the driving factor and most consistent predictor of prejudice in comparison to other relevant constructs,” the paper states.

In the Israel-based study, people with a higher belief in evolution were more likely to support peace among Palestinians, Arabs and Jews. In the study involving countries in the Islamic world, belief in evolution was associated with less prejudice toward Christians and Jews. And in the study based in Eastern Europe, where Orthodox Christians are the majority, a belief in evolution was linked with less prejudice toward gypsies, Jews and Muslims.

Syropoulos posits that a belief in evolution may expand people’s “moral circle,” leading to a sense that “we have more in common than things that are different.” The findings also suggest that “teaching evolution seems to have side effects that might make for a better or more harmonious society,” Leidner adds.

The next step, the researchers say, is to investigate how evolution is taught in the classroom and work toward developing models to study and strengthen the positive effects.