The number of Americans with no religious affiliation has grown from 16% in 2007 to 28% in 2023. At first glance, this suggests that naturalism, though not common, is hardly rare. But rejecting organized religion is not the same as rejecting the supernatural. If we look specifically at naturalism (the idea that natural, rather than supernatural, laws and forces are the only ones at work in the universe) we see that it remains rare.
Pew Research divides the religiously unaffiliated, who they call “nones”, into three groups: atheists (5% of U.S. adults), agnostics (6%), and those who say they are “nothing in particular” (18%). The following is a table of the beliefs each group holds:
| Belief | Atheist | Agnostic | Nothing in particular |
|---|---|---|---|
| Believe in “God as described in the Bible” | <1% | 3% | 20% |
| Believe in “hell” | 3% | 13% | 41% |
| Believe in “heaven” | 4% | 18% | 51% |
| Feel presence of something from beyond this world (at least several times a year) | 8% | 15% | 33% |
| Believe crystals, jewels, or stones can have spirits/spiritual energy | 9% | 25% | 36% |
| Had a strong feeling that someone dead was communicating with them | 15% | 24% | 44% |
| Had a sudden sense of connection with something from beyond this world | 18% | 36% | 44% |
| Believe cemeteries or other memorial sites can have spirits/spiritual energy | 18% | 43% | 56% |
| Think of themselves as spiritual | 20% | 41% | 59% |
| Believe in some other higher power (not God as described in the Bible) | 22% | 64% | 63% |
| Believe there is something spiritual beyond the natural world (even if we can’t see it) | 24% | 61% | 75% |
| Believe parts of nature (mountains, rivers, trees) can have spirits/spiritual energy | 26% | 55% | 62% |
| Believe humans have a soul or spirit in addition to their physical body | 31% | 60% | 78% |
| Believe animals other than humans can have spirits/spiritual energy | 33% | 59% | 68% |
Even among atheists, disbelief stops at the Biblical God. About a third of them still believe in souls. A quarter believe that nature contains spirits or energies. A fifth believe in some kind of higher power. A few even say they believe in heaven or hell. Agnostics and the “nothing in particular”s report even higher levels of supernatural belief: most say they believe in a higher power, and half of the latter believe in heaven.
How many people reject all supernatural beliefs? The survey allows us to estimate an upper bound. 19% of the “nones” express disbelief in all of the following: “God as described in the Bible”, “some other higher power”, “humans have a soul or spirit”, “something spiritual beyond the natural world [exists]”, “heaven”, and “hell”. Taking into account the proportion of “nones” in the US population, we have an upper bound of 5.3% of US adults not holding any spiritual or religious beliefs, much lower than the 28% of adults who are merely “not religious”.