First-person accounts of near-death experiences have been all over the bestseller lists in recent years. Think of Eben Alexander’s Proof of Heaven, Anita Moorjani’s Dying to Be Me, and Todd Burpo’s Heaven Is for Real. It’s hard to read these narratives without having one’s perspective on death–whatever it is–profoundly challenged. And yet individual stories of near-death experiences leave something out: they don’t give us a sense of just how pervasive and consistent this phenomenon is.

As far back as 1982, a Gallup poll concluded that 5% of the U.S. population had had a near-death experience. That was 11.6 million people in 1982. (Today, 5% puts us at 16.2 million.) That is an astounding number of Americans to have experienced a “life beyond death,” but my own experience is consistent with those numbers. If anything, it suggests that they are on the conservative side. Among my own family members, I can count two people who’ve had near-death experiences–and my family numbers substantially less than 40.

But it’s not just the numbers that are astounding. In his 2010 book Evidence of the Afterlife, Dr. Jeffrey Long presents the results of his 12-year study of more than 1,300 near-death experiences collected from around the world, by his website nderf.org. Surprise! It’s not just Americans who have near-death experiences. And it’s not just folks from Judeo-Christian countries. It’s not just cardiac arrest patients, either. Or whatever subset of the population you think might be prone to having end-of-life “hallucinations.”

Dr. Long clearly lays out the evidence that very similar types of near-death experiences happen to people in very different cultures and very different states of bodily dysfunction. For instance, you might think that near-death experiences can be explained as hallucinations created by an oxygen-deprived brain (a state known as hypoxia). Set aside the fact that near-death experiences are extremely lucid, a far cry from the confusion known to be induced by hypoxia. How do you explain the fact that the very same types of near-death experiences happen to people who are under general anesthesia, when they’re not supposed to be capable of any conscious experience whatsoever?

Dr. Long’s study statistically compared the content of NDEs (near-death experiences) that occurred under general anesthesia to those that did not. He writes, “there were no significant differences in the responses to any of the thirty-three survey questions between the two groups, with the exception that anesthesia-associated NDEs reported encountering a tunnel more often.” One of Long’s survey questions specifically asked participants, “How did your highest level of consciousness and alertness during the experience compare to your normal everyday consciousness and alertness?” It would stand to reason that, if a near-death experience were merely a product of brain chemistry, the presence of anesthesia, even if it didn’t do its job of preventing all conscious experience, would at least make one’s experience less sharp. Right?

That’s not what the survey found. “For the NDEs described as occurring under general anesthesia, 83 percent of the respondents answered ‘More consciousness and alertness than normal’ to this question, compared to 74 percent for all other NDEs.” That is, the folks under general anesthesia were reporting exceptionally clear experiences more often than the folks who weren’t! Now, given the sample sizes (23 anesthesia NDEs and 590 non-anesthesia NDEs in the survey), this difference is not statistically significant. But the mere fact that there is no statistically significant difference in level of consciousness and alertness in NDEs under anesthesia from those not under anesthesia is remarkable! In NDEs, something is going on that is not limited by the brain state of the person in question.

This conclusion is underscored by two other radical pieces of evidence. The first is the general fact that experiencers of NDEs (known in the literature as “NDErs”) often report having perceived during their NDE information that they had no way of perceiving through the normal sensory apparatus of their bodies. Some have seen details of their surgical operations while their eyes were taped shut. Others have heard conversations had by their loved ones in a far-off location. You might say all this is unscientific anecdote, but researchers have compared the accuracy of NDErs’ accounts of the CPR performed on them with the descriptions of their CPR given by patients who did not have NDEs. One such study, conducted by cardiologist Michael Sabom, concluded that (in Dr. Long’s words), “NDErs with out-of-body experiences were far more precise than those in the control group in accurately describing their resuscitations.”

But there are cases even more astounding than this. Consider the case of Vicki, who became blind shortly after birth when a problem with the oxygen regulation of her incubator damaged her optic nerves. She never even had a concept of what vision was like. Until her near-death experience. During her NDE, she was suddenly able to see her own body and all of the medical personnel attempting to help her. Her experiences are related in a separate book: Mindsight by Kenneth Ring and Sharon Cooper. As she says there, “This was the only time I could ever relate to seeing and to what light was, because I experienced it.”

As Long points out in the introduction to his book, we might not find any one of these lines of evidence completely convincing on its own. But when all of these different elements begin to pile up–when you hear these things not just from one person who wrote a best-selling book but from thousands of people of all different ages, religious beliefs, cultures, and physical capacities, from historical eras stretching back before the birth of Christ and then from your own friends and relatives as well–it’s hard to escape the conclusion that this stuff is real. That what goes on in our brains isn’t even the half of it. That consciousness is way wider than our current scientific knowledge can comprehend. And that it sure looks like the demise of our physical bodies isn’t the end.

One more tidbit I forgot to mention: If NDEs are just hallucinations, why is it that 96% of the people that NDErs report encountering “on the other side” are people who are deceased?