Trust in scientists has jumped 10 percentage points in three years. (Marvin Joseph/The Washington Post)

A new survey adds to mounting evidence that trust in scientists is rising overall in the United States, but that there are differences between Republicans and Democrats and between races. A poll published by the Pew Research Center on Friday found that 86 percent of respondents say that they trust scientists at least “a fair amount,” up from 76 percent three years ago.

What’s different about the new poll is that it asked people their views on the “role of scientific experts in policy matters.” It’s one thing to trust scientists; it’s another to trust them leading policy.

Six out of 10 people say scientists belong in policy debates. The rest say they should “focus on establishing sound scientific facts and stay out of public policy debates.” The survey documents a notable partisan split. Among Democrats, 73 percent say scientists should be active in policy debates, compared with 43 percent of Republicans.

Participation in policy debates can take many forms. Bill Nye, the “Science Guy” television host, debated about evolution with creationist Ken Ham onstage in 2014, a type of debate many scientists avoid because it implies that the two sides have equal standing. Scientists pen “open letters” in scientific journals to petition governments; a letter published in the journal Nature last week called on U.N. member countries to make environmental destruction a war crime. Federal scientists commonly present the work they do in policy settings such as congressional hearings, a type of engagement that has been blocked in some cases for climate experts under the Trump administration.

The survey asked whether scientists are better at making science policy decisions than other people and uncovered a partisan divide here, too. A majority of Democrats agree with 2020 Democratic presidential candidate and former congressman Beto O’Rourke (Tex.), who said of his climate action plan during Tuesday’s Democratic debate: “Let’s actually have the scientists drive this.”

When it comes to addressing a science-related policy problem, 54 percent of Democrats see scientific experts as better at decision-making than most people.

President Barack Obama is in this camp, too. He stacked the leadership ranks of federal agencies with scientists such as nuclear physicist Ernest Moniz as secretary of energy and marine ecologist Jane Lubchenco as administrator of the National Oceanic and Atmospheric Administration. Among Republicans, 34 percent would likely do the same.

The differences between Republicans and Democrats may be linked to fundamental differences in how they view bias.

The Republicans polled were more likely to say that scientists are just as susceptible to bias as other people. For Republicans with high scientific knowledge, 64 percent say scientists are susceptible to bias. About 40 percent of Democrats, regardless of their familiarity with science, see scientists in that way.

Putting politics aside, the new survey found a jump of 10 percentage points since a similar survey in 2016 in the percentage of people expressing trust in scientists.

“As a scientist, I’m pretty cheerful about that,″ said Susan Fiske, a psychologist at Princeton University who studies trust and was not involved with the survey. Americans trust scientists about as much as they trust the military, more than religious leaders and a lot more than the news media.

Cary Funk, director of science and society research at Pew and co-author of the report, described people’s attitude toward scientific experts as “soft support.” Her team surveyed a nationally representative group of 4,464 adults in 50 states in January.

Another divide between Republicans and Democrats emerges when asking people about their views on different types of experts. Almost 70 percent of Democrats have a positive view of environmental researchers, compared with 40 percent of Republicans.

Overall, people trust practitioners, such as dietitians or physicians, more than they trust researchers. “Trusting a group or profession comes from thinking about what their intentions and motives are,” Fiske said. “The motive of the research scientist can be murky. But with a doctor, you assume [the motive] is to help people.”

A study from 2016 suggested that the eccentric, emotionally distant scientist stereotype — strengthened by shows such as “The Big Bang Theory” — partially explains why experts who do research are seen as “capable of immoral conduct.”

Essentially, the study found that this attitude is less about thinking that scientists are bad people and more about seeing them as being so robotlike that no one could possibly know their motives.

“I think part of what’s going on here is that the more [people] know, the more they trust,” Fiske said.

Knowing more about and developing trust in a scientist’s work can be as simple as seeing a selfie on Instagram. A study published in May found that scientists who post candid self-portraits of themselves doing scientific work were perceived as warmer and more trustworthy. Scientists who tell stories can get similar results, studies have found.

The new Pew poll also found that African Americans and Hispanics have more skepticism than whites for health researchers.

More than 70 percent of blacks see misconduct as a problem among health experts. These views have a history in the Tuskegee syphilis experiment, forced sterilizations, and other atrocities committed by 20th-century medical professionals. African Americans still don’t receive equal preventive medical care or pain management, particularly women, and black women are more likely to die in childbirth.

“There’s data that backs that up. But, for a person of color, it’s also a sense . . . a feeling when you walk in the hospital . . . that drives mistrust,” said Jamila Michener, a social scientist at Cornell University who studies public policy and was not involved in the survey.

Increasing African Americans’ confidence in physicians and health researchers, according to Michener, will involve addressing implicit bias, stereotypes and racism — in their historical and present-day forms.

The Washington Post reached Michener while she was conducting research in Atlanta’s suburbs, surveying people’s experiences with public benefits. She said Pew’s results were sad but not at all surprising. “In fact, I feel like the mistrust [of doctors] has literally been the theme of my day,” she said.

“Just earlier, I interviewed an African American women who has severe physical disabilities,” Michener said. “She’s having problems getting care through Medicaid. She told me flat out ‘You can’t trust these people.’ "