Americans have little doubt about the scientific evidence that smoking can cause cancer. However, a bigger portion of Americans still question some of the basic concepts of modern science, according to a new Associated Press-GfK poll.

In the survey, with a representative sample of 1,012 U.S. adults age 18 or older, respondents were asked to rate their confidence in several statements about science and medicine.

What the survey revealed was surprising. Overall, Americans show more skepticism than confidence in the scientific concept that a Big Bang created the universe 13.8 billion years ago.

There was also considerable doubt about the science behind global warming and the age of the Earth.

The most broadly accepted scientific statement was that smoking causes cancer, with a whopping 82 percent of respondents saying they were extremely or very confident that it did.

CBS News

Views on science may be tied to what people see with their own eyes. The closer an issue is to their own bodies, and the less complicated, the easier it is for people to believe, suggested John Staudenmaier, a Jesuit priest and historian of technology at the University of Detroit Mercy.

Almost four in ten people in the survey said that they were not confident in the average temperature of the world is rising, or that life on Earth evolved through natural selection, and about a third doubted that the Earth was 4.5 billion years old. However, a majority was still at least somewhat confident in the concepts.

However, when it came to the Big Bang, a majority -- 51 percent -- had little or no confidence in the science.

"It is enormously distressing that science, which is our most powerful means for gaining insight into the world, insight into truth, is so mistrusted by so many people," Brian Greene, a professor of physics and mathematics at Columbia University, told CBS News.

Greene, who co-founded the World Science Festival and World Science U. to help educate and excite the public about science, says understanding scientific ideas is not just academic -- it's essential to a vital democracy. "Issues like climate change or nanoscience or genetically modified foods -- I mean all of these issues, and a thousand others, are scientific at their core," he said.

Role of politics and religion

Political and religious values play an important role in a person's belief in science, the AP noted. Democrats were more likely than Republicans to express confidence in evolution, the Big Bang, the age of the Earth and climate change. As faith in a supreme being rises, confidence in the Big Bang, climate change and the age of the Earth decline, according to the poll.

"When you are putting up facts against faith, facts can't argue against faith," said 2012 Nobel Prize winning biochemistry professor Robert Lefkowitz of Duke University. "It makes sense now that science would have made no headway because faith is untestable."

Daniel Willingham, a professor of psychology at the University of Virginia, told CBS News that people's world views and social relationships influence what they believe. People do understand that scientists produce information "that ought to be believed," but there are other motivations, such as social norms or fear of the unknown, that may affect their views.

"They believe them for social reasons -- you have been maintaining your relationships with people; holding certain beliefs is part of that," Willingham told CBS News. "When you're arguing with someone, no one ever says 'No, I just won't believe that because it's too damn frightening to believe' -- they're going to give you rational reasons...[It's] very difficult to persuade someone when that's their motivation."

People who take the word of the Bible literally are even less likely to believe in evolution, the age of the Earth or Big Bang. But Francisco Ayala, a former priest and professor of biology, philosophy and logic at the University of California, Irvine, noted that these three scientific concepts can be compatible with the belief in God.

"The story of the cosmos and the Big Bang of creation is not inconsistent with the message of Genesis 1, and there is much profound biblical scholarship to demonstrate this," said Darrel Falk, a biology professor at Point Loma Nazarene University and an evangelical Christian.Willingham says that some scientific findings -- such as that smoking causes cancer -- do not challenge religious beliefs, but when science appears to directly contradict their faith -- such as evolution versus creationism -- people are more likely to find it upsetting.

Andrew Shtulman, professor of psychology at Occidental College says some people may not believe in science because it draws on evidence that they don't experience in their everyday lives.

"Everyone draws conclusions about the world around them - scientists and non-scientists alike - but non-scientists base those conclusions on much weaker evidence: a single observation, a gut feeling, hearsay from others," Shtulman told CBS News via email. "When those 'homespun' conclusions contradict the conclusions of science, it's difficult to recognize that they rest on much flimsier grounds."

The results of the poll are troubling to some scientists, who say it highlights "the iron triangle of science, religion and politics," according to Anthony Leiserowitz, director of the Yale Project on Climate Change Communication.

"Science ignorance is pervasive in our society, and these attitudes are reinforced when some of our leaders are openly antagonistic to established facts," said 2013 Nobel Prize in medicine winner Randy Schekman of the University of California, Berkeley.

Ignorance can be dangerous

Ignorance of science could also prove to be dangerous for America as well, as Willingham notes that parents' reluctance towards vaccines can harm others by spreading disease. Science is not meant to dictate policy, he says. Rather, it is used to tell others what the state of the world is, and how officials respond to that is a statement of values.

Interest groups -- political, business and religious -- can also play a role in the public's scientific beliefs, with campaigns being waged against vaccines, climate change and evolution, according to Duke's Lefkowitz. Yale's Leiserowitz agreed, but added that sometimes science wins against even the most well-financed and loud opposition.

The widespread understanding that smoking causes cancer -- noted in the study -- can be said to be a result of "very public, very focused public health campaigns," according to Alan Leshner, chief executive of the world's largest scientific society, the American Association for the Advancement of Science. A former acting director of the National Institute of Mental Health, Leshner said he was encouraged by the public's acceptance that mental illness is a brain disease, something few believed 25 years ago, before just such a campaign.

"Science, in its really pure form, is just telling you what the state of the world is," Willingham said. "The more in-tune with reality your beliefs are, the more you are in a position to make a wise decision."

Shtulman says scientists can help people understand science by explaining their findings with everyday terms, and spent time clarifying much of the misinformation that gets spread in the media.

"Many people get hung up on buzzwords like 'evolution,' 'cloning,' 'stem cell,' or 'climate change,' which they do not necessarily understand, but have formed opinions about nonetheless," Shtulman said.

"These opinions effectively block the reception of new information, even when that information is not itself controversial. The more scientists (and the media) can avoid sensationalizing scientific findings, the better."

Danielle Elliot contributed reporting to this piece. The Associated Press also contributed reporting.