About three-quarters of Americans believe in the Virgin Birth, according to a recent Pew survey.
That's not surprising, experts say.
Belief in Jesus' immaculate conception isn't such a leap once you accept the possibility of miracles and the supernatural. And from a cognitive perspective, the human brain is primed for a belief in God and the supernatural.
Those polls are "evidence that most people know scientific knowledge is not the only kind of knowledge," said Stacy Trasancos, a popular blogger on science and Catholicism and the author of "Science Was Born of Christianity" (Amazon Digital Services, 2013). "People find it reasonable to believe in the reality of the supernatural."
Belief in Mary's virginity comes down to a belief in miracles, or events that operate outside the normal laws of nature. A 2010 Pew study found that 80 percent of Americans believe in miracles — roughly on par with the 73 percent who believe that Jesus was born to the Virgin Mary. [The Top 10 Most Controversial Miracles]
In some ways, the human brain is primed to hold these types of supernatural beliefs.
In a 2013 study detailed in the journal Perspectives on Psychological Science, Will Gervais, a psychologist at the University of Kentucky, has proposed that the ability to conceive of a supernatural God is a byproduct of the so-called theory of mind, or the human ability to imagine that others have a mind of their own.
"Over 90 percent of Americans believe in God, in part, because we have brains that are well-suited to agent detection," Wade Rowatt, a psychologist and neuroscientist at Baylor University in Texas, wrote in an email. "When there’s a sound in the bush, we assume something generated the sound. If nothing's there, we have the capacity to infer it could have been the wind or a mysterious spirit force."
In addition, human beings have a built-in cognitive bias to believe in mind-body dualism, or that the mind and body are inherently separable. That belief may come about because people have separate cognitive systems for navigating the physical world versus the social world, according to a 2007 study in the journal Developmental Science.
From the intuitive belief in a soul, it's just a short hop to believing in a God, the study argues. From there, supernatural events such as the Virgin Birth don't seem too far-fetched.
In addition, human beings have a natural tendency to view metaphors and symbols more literally over time, said Philip Clayton, who studies the relationship between science and religion at Claremont School of Theology in California.
"Children don't distinguish between the literal and the symbolic," Clayton told LiveScience. That tendency to conflate the symbolic and the concrete may still persist somewhat into adulthood, leading people to believe metaphorical stories as literal truth, he said.
So Jesus' miraculous birth, which some theologians say was originally meant to symbolize purity, came to be viewed as a true, historical account, he said.
Can scientists believe?
Miracles are a tougher sell for scientists, who spend all day trying to explain the universe using natural laws. But some scientists don't think science and belief in miracles such as the Virgin Birth must be mutually exclusive. [6 Interesting Facts About Jesus, the Man]
That's because it's not necessary to understand every aspect of something to believe in its truth or importance, said Andrew Briggs, a nanomaterials scientist at the University of Oxford who is Christian.
For instance, physicists don't agree about what really happens when they take a measurement of tiny particles in quantum systems. But at the same time, quantum mechanics, which governs the behavior of the very small, has shown itself to be a robust theory that works again and again, even if scientists don't understand all of it, Briggs said.
Similarly, "there are aspects of what happens when I pray to which I don't really have a satisfactory account," Briggs told LiveScience. Yet there is enough other evidence that prayer is important for him to continue the practice.
Trasancos, who trained as a chemist and converted to Catholicism in mid-life, used a variant of the scientific method to arrive at her religious beliefs.
"In science they say there are these physical laws and you go into a lab and test them empirically," Trasancos said. "With moral laws, I tried them in my life — tested them, even when I wasn't sure how they can possibly work. I tried them and saw the truth of them after I tested them."