Scientists have topped a survey of trusted professions, with adults in the US more confident that they act in the public’s best interests than employees from any other line of work studied.

The survey found that confidence in scientists has risen markedly since 2016 and more than half of American adults believe the specialists should be actively involved in policy decisions surrounding scientific matters.

The upswing in public trust, a rise of 10 percentage points since 2016, led to 86% of US adults expressing at least a “fair amount” of confidence that scientists put the public interest first. The trust rating placed scientists above politicians, the military, business leaders, school principals and journalists.

Trust in non-scientific professions has remained largely stable since 2016 with school heads on 77%, religious leaders on 57%, journalists on 47%, business leaders on 46% and politicians earning the lowest mark at 35%, the survey by the Pew Research Center in Washington DC found.

Cary Funk, the director of science and society research at the organisation, said it was unclear why confidence in science had grown but described much of the public trust as “soft” support. “It is a pattern we see a lot,” she said. “At the highest level, public views tend to be positive, but there tends to be more soft support.”

Delving deeper into the figures shows the proportion of people with a “great deal” of confidence in scientists has risen from 21% to 35% since 2016, meaning about half of the people who trust scientists are more reserved in their support.

A similar picture emerged last year from the Wellcome global monitor, a study of worldwide views on science and health that quizzed more than 140,000 people from over 140 countries. Overall, it found 18% had a high level of trust in scientists, but 54% expressed only a medium level.

The Pew survey of 4,464 people, selected as a nationally representative sample, reveals a number of intriguing trends. While trust in scientists to provide fair and accurate information rises with people’s familiarity with science, there are marked divisions along party lines. For example, far more Democrats (43%) than Republicans (27%) said they had a “great deal” of confidence in scientists.

The different levels of trust appeared to shape people’s views on where scientists’ voices should be heard – and where they should refrain. Nearly three-quarters of Democrats wanted scientists actively involved in thrashing out policy, whereas a majority (56%) of Republicans felt the researchers should stick to establishing facts and stay out of such debates.

In a similar vein, more Democrats than Republicans (54% to 34%) thought scientists made better policy decisions than others on scientific matters. Democrats were also more inclined than Republicans (62% to 44%) to believe scientists made their decisions based solely on the facts.

On both sides of the political divide, more scientifically literate respondents were concerned about biases that may cloud scientists’ thinking. Among Republicans, 39% with little scientific knowledge thought scientists were just as biased as other people. But for Republicans more familiar with science, the figure shot up to 64%. The same trend, though far less pronounced, was seen in Democrats.

As found in previous surveys, environmental science proved the most divisive issue for US adults, suggesting that the cause and impact of the warming climate will continue to be argued across party lines. A solid majority of Democrats (70%) had “mostly positive” views on environmental scientists, but only 40% of Republicans felt the same. Similarly, nearly half of Democrats (47%) trusted environmental scientists to provide fair and accurate information about their work “all or most of the time”, a statement less than one in five Republicans agreed with.

The survey suggests there is plenty of room for scientists to improve. It found the public has major doubts about scientists routinely declaring conflicts of interest; admitting their mistakes; and in cases of misconduct, facing serious consequences. More than half of respondents said they trusted scientific findings more when researchers made the data publicly available.