The Books Interview: Nicholas Humphrey

Solving the problem of consciousness.

Most of the Critics section in this week's issue of the New Statesman, out today, is devoted to a philosophy special. The philosopher and writer Raymond Tallis reviews two of the latest contributions to the burgeoning science of consciousness, Antonio Domasio's Self Comes to Mind and Nicholas Humphrey's Soul Dust. Humphrey recently spoke to the New Statesman about his new book.

Can you explain the title of your new book, Soul Dust?
I'm arguing that consciousness is like a kind of fairy dust which turns everything it touches into gold. "Dust" means matter too, but what I also want to do is reintroduce the soul as a respectable issue for evolutionary psychology and philosophy.Soulfulness or spirituality is a major achievement of natural selection. It allows us to live in this extraordinary ecological net which I call "soul land".

What's distinctive about your approach?
Philosophers and scientists have assumed that consciousness must be giving us some new skill or faculty of cognition. Then they get verypuzzled, because it doesn't seem to. I argue that consciousness changes our psychology in terms of our attitude toward the world we live in, rather than giving us a new skill.

Why do you want to make the idea of the soul respectable again?
My position as a natural historian of consciousness is to take seriously the way consciousness affects people's outlook on life. They may, for example, have the Christian idea of the soul, with all the baggage that comes with it.But spirituality and the belief in the soul actually came before religion, and religion has been parasitic on them. I don't agree with the view, now rather common view among evolutionary psychologists, that religion was evolutionarily adaptive.

How do you account for the emergence of religion then?
It emerged for cultural reasons. It's an extraordinarily powerful "meme", if I can use that word. But memes don't have to serve the interests of the hosts who carry them. I'm not arguing that religion is a bad thing in terms of the consequences it has. My point is that people had a spiritual side before religion took advantage of it.

You describe consciousness as a "magical mystery show" that human beings lay on for themselves. Why do we do that?
Sensation didn't have to have the qualities it does. They seem to have been elaborated by some really clever things going on in the brain. The question is why we have evolved them? My answer is that they change our relationship to the world and make it seem a more mysterious and magical place, and make us, as the enchanters of the world, see to be extraordinary, almost supernatural beings.

Indeed, you point out that we are tempted to treat consciousness as something "out of this world".
It seems to be something that is beyond explanation in terms of what we know about the material world. That's a claim which many people, religious believers and philosophers, always make.

So do you see your job in this book as breaking the spell that consciousness puts on us?
I don't think I'm breaking it. I'm drawing attention to it, and marvelling at it. Of course, I'm also trying to give a material explanation for what looks like magic. But the emphasis is on the fact that it does look like magic, and the questions I go on to ask are about what purpose it's serving.

What about animals which are conscious but don't, as far as we can tell, feel so special?
There may be varieties of consciousness which have at least some of the psychological effects I described and which we could recognise in dogs or chimpanzees, say. We should be able to see signs of it in the playfulness and the exuberance of an animal, in the way it delights in being itself.

Your background is in experimental psychology rather than philosophy. What do your more empirically minded colleagues think of what you're doing?
I'm waiting to see. The challenge will be to "prove it". If I am doing this in the name of science, then I ought to come up with predictions. But that is a tough order. I just hope that the ideas are taken seriously and that people who are much cleverer than me will realise that this could haveinteresting and testable consequences.

Interview by Jonathan Derbyshire
Nicholas Humphrey's "Soul Dust: The Magic of Consciousness" is published by Quercus (£18.99)

Jonathan Derbyshire is Managing Editor of Prospect. He was formerly Culture Editor of the New Statesman.

Davide Restivo at Wikimedia Commons
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Scientists have finally said it: alcohol causes cancer

Enough of "linked" and "attributable": a new paper concludes that alcohol directly causes seven types of cancer.

I don't blame you if you switch off completely at the words "causes cancer". If you pay attention to certain publications, everything from sunbeds, to fish, to not getting enough sun, can all cause cancer. But this time, it's worth listening.

The journal Addiction has published a paper that makes a simple, yet startling, claim: 

"Evidence can support the judgement that alcohol causes cancer of the oropharynx [part of the throat], larynx, oesophagus, liver, colon, rectum and [female] breast"

So what's especially significant about this? 

First, scientists, unlike journalists, are very wary of the word "causes". It's hard to ever prove that one action directly led to another, rather than that both happened to occur within the same scenario. And yet Jennie Connor, author of the paper and professor in the Preventive and Social Medicine department at the University of Otago, New Zealand, has taken the leap.

Second, alcohol not only causes cancer of one kind – the evidence supports the claim that it causes cancer at seven different sites in our bodies. There was weaker evidence that it may also cause skin, prostate and pancreatic cancer, while the link between mouth cancers and alcohol consumption was the strongest. 

What did we know about alcohol and cancer before?

Many, many studies have "linked" cancer to alcohol, or argued that some cases may be "attributable" to alcohol consumption. 

This paper loooks back over a decade's worth of research into alcohol and cancer, and Connor concludes that all this evidence, taken together, proves that alcohol "increases the incidence of [cancer] in the population".

However, as Connor notes in her paper, "alcohol’s causal role is perceived to be more complex than tobacco's", partly because we still don't know exactly how alcohol causes cancer at these sites. Yet she argues that the evidence alone is enough to prove the cause, even if we don't know exactly how the "biologial mechanisms" work. 

Does this mean that drinking = cancer, then?

No. A causal link doesn't mean one thing always leads to the other. Also, cancer in these seven sites was shown to have what's called a "dose-response" relationship, which means the more you drink, the more you increase your chances of cancer.

On the bright side, scientists have also found that if you stop drinking altogether, you can reduce your chances back down again.

Are moderate drinkers off the hook?

Nope. Rather devastatingly, Connor notes that moderate drinkers bear a "considerable" portion of the cancer risk, and that targeting only heavy drinkers with alcohol risk reduction campaigns would have "limited" impact. 

What does this mean for public health? 

This is the tricky bit. In the paper, Connor points out that, given what we know about lung cancer and tobacco, the general advice is simply not to smoke. Now, a strong link proven over years of research may suggest the same about drinking, an activity society views as a bit risky but generally harmless.

Yet in 2012, it's estimated that alcohol-attributable cancers killed half a million people, which made up 5.8 per cent of cancer deaths worldwide. As we better understand the links between the two, it's possible that this proportion may turn out to be a lot higher. 

As she was doing the research, Connor commented:

"We've grown up with thinking cancer is very mysterious, we don't know what causes it and it's frightening, so to think that something as ordinary as drinking is associated with cancer I think is quite difficult."

What do we do now?

Drink less. The one semi-silver lining in the study is that the quantity of alcohol you consume has a real bearing on your risk of developing these cancers. 

On a wider scale, it looks like we need to recalibrate society's perspective on drinking. Drug campaigners have long pointed out that alcohol, while legal, is one of the most toxic and harmful drugs available  an argument that this study will bolster.

In January, England's chief medical officer Sally Davies introduced some of the strictest guidelines on alcohol consumption in the world, and later shocked a parliamentary hearing by saying that drinking could cause breast cancer.

"I would like people to take their choice knowing the issues," she told the hearing, "And do as I do when I reach for my glass of wine and think... do I want to raise my risk of breast cancer?"

Now, it's beginning to look like she was ahead of the curve. 

Barbara Speed is a technology and digital culture writer at the New Statesman and a staff writer at CityMetric.