Tuesday 10 June 2014

Heavenly confirmation bias

Here's a video[1] of an Intelligence Squared[2] debate, on the motion that "Death is Not Final". The Three Pauls talked briefly about this on Skepticule episode 73[3], but I'm using this blogpost to set down a slightly more detailed account of my reactions to how the debate proceeded.


Eben Alexander[4] is a neurosurgeon who claims to have seen Heaven during a near-death experience (NDE) while under the knife on the operating table. He wrote a book about it, Proof of Heaven[5], using his credentials as a man of medical science to persuade the general public to take him on his word that he knows there is an afterlife because he was given a tour of the place. The book is a bestseller.

Supporting Alexander was Raymond Moody[6], who apparently coined the phrase "near-death experience"[7], but apart from that I don't think he contributed much of substance to the discussion. Indeed he seemed to be on another (astral?) plane altogether.

Opposing Alexander and Moody were Sean Carroll[8] and Steven Novella[9], who argued that, yes, death is final. Sean Carroll is a cosmologist and a good debater — as we saw recently[10] when he took on Christian apologist William Lane Craig[11], refuting Craig's arguments with ease and not a little aplomb. Steven Novella is a neurologist and another accomplished debater, so he was a particularly good choice to be put up against the afterlife proponents. I should point out here that though Alexander has made much of his credentials as a neurosurgeon, as far as I'm aware this is not the same as a neurologist (which is what Novella is). The difference between neurology and neurosurgery can probably be likened to that between fluid dynamics and plumbing, or between botany and gardening.

As is usual with Intelligence Squared, the debate format was semi-formal with a moderator, and an audience-vote before the debate and another afterwards. All four participants made opening statements, then there were rebuttals and questions. Alexander read his opening statement somewhat stiffly, whereas Carroll and Novella spoke extempore directly to the audience without notes. Moody, it seemed to me, just waffled.

Alexander and Moody took the position that consciousness is complicated and not understood, and therefore it might have a component that is separate from the brain. Moody was unhelpfully speculative on this point, while Alexander claimed to have proved it. Carroll and Novella on the other hand maintained that there is no evidence for consciousness existing apart from the brain, and that consciousness — and anything we describe as "mind" — is inextricably linked to the brain. Novella's phrase for this was: "The mind is what the brain does." Though consciousness is at present unexplained, much research is now under way, and the current lack of a full explanation is no justification for unevidenced claims for conciousness being mind-independent.

Alexander claimed that his tour through the afterlife took place when his brain was incapable of registering anything, but as Novella pointed out, he cannot know this. We don't know what time it is when we dream. As I see it, there's an even deeper flaw with Alexander's claim, which to me is so obvious I wonder how NDE's can ever be taken as evidence for anything other than being "near death". If Alexander's brain was all but completely non-functioning, how can he trust anything he perceived during that period?

By way of analogy, imagine this scenario. At a notoriously dangerous intersection a horrific traffic accident takes place, involving several vehicles, and everyone involved is killed. When the authorities arrive on the scene they find that one of the cars is relatively new, and so they decide to interrogate the engine management system (EMS) using standard computerised diagnostic tools. Though the car is a write-off, the electronics appear to be still partly functioning. The EMS is able to respond to the diagnostic tools, reporting that the vehicle is now — at the very moment the tools are probing — travelling at 90 miles per hour without consuming a drop of fuel. What does this indicate? Does it indicate that despite appearances (a crushed car incapable of motion) the vehicle is in fact moving very fast with impossibly low fuel consumption? Of course not — it indicates that the EMS is damaged, and its reports cannot be trusted.

This debate was a splendid example of confirmation bias. The idea of life after death is so attractive, some people will ignore the counter-evidence no matter how obvious it appears. Even after Novella had clearly stated that there were no reliably documented cases of NDEs and out-of-body experiences that produced information that could not have been obtained any other way, Alexander went on to state that there were too many cases that couldn't be explained — though he provided no citations for these.

Alexander further illustrated his confirmation bias (I'll assume that's what it was, rather than impute nefarious motives) when he stated that Carl Sagan[12] wrote in The Demon-Haunted World[13] that he was open to the possibility of consciousness independent of the brain — he even quoted the page number. Alexander was either naïve or mistaken, because while Novella could only splutter in astonishment that Sagan would never have said anything of the sort, several of those watching the debate's live stream simply looked up the page, photographed it, and posted the image on Twitter with the relevant hashtag during the debate — thus giving the lie to Alexander's rash claim.

At one point Alexander challenged the other side to provide a one-sentence explanation of consciousness, knowing of course that there currently isn't one. Novella stated again that there was ongoing research, but as Jonathan MS Pearce[14] has pointed out[15], he missed the chance to demand a one-sentence explanation of God. Despite this, and perhaps unsurprisingly, the after-debate vote confirmed that the motion "Death is Not Final" had been comfortably defeated.

Is Alexander's insistence that he has "proof of Heaven" based on anything more than confirmation bias? His stance seems so obviously flawed that I'm left wondering if there aren't some effects of brain-damage hanging around after his near-death experience. That's the kinder interpretation. Another interpretation, less kind, might be that a neurosurgeon's salary could be considered a pittance in comparison to royalties from a bestselling book.


1. YouTube: Death is Not Finalhttp://youtu.be/h0YtL5eiBYw
2. Intelligence2http://www.intelligencesquared.com/
3. Skepticule 073 — http://www.skepticule.co.uk/2014/05/skepticule-073-20140519.html
4. Eben Alexander — http://en.wikipedia.org/wiki/Eben_Alexander_%28author%29
5. Proof of Heavenhttp://www.amazon.co.uk/Proof-Heaven-Neurosurgeons-Journey-Afterlife-ebook/dp/B008TTPQXA
6. Raymond Moody — http://en.wikipedia.org/wiki/Raymond_Moody
7. Near-Death Experience — http://en.wikipedia.org/wiki/Near-death_experience
8. Sean Carroll — http://preposterousuniverse.com/
9. Steven Novella — http://en.wikipedia.org/wiki/Steven_Novella
10. YouTube: God & Cosmologyhttp://www.youtube.com/watch?v=07QUPuZg05I
11. William Lane Craig — http://en.wikipedia.org/wiki/William_Lane_Craig
12. Carl Sagan — http://en.wikipedia.org/wiki/Carl_Sagan
13. The Demon-Haunted Worldhttp://www.amazon.co.uk/The-Demon-haunted-World-Science-Candle/dp/1439505284
14. Jonathan M. S. Pearce — http://www.skepticink.com/tippling
15. "Carroll & Novella vs Alexander & Moody. Some terrible, terrible arguments" — http://www.skepticink.com/tippling/2014/05/09/carroll-novella-vs-alexander-moody-some-terrible-terrible-arguments/