Monday, February 20, 2006

Gut thinking

We humans often pride ourselves on our rationality, and on our ability to make complex decisions through reasoning power. In recent decades, however, the role accorded to reason in driving our decisions and behaviour has been called into question by many psychologists.

Experiments have revealed that our decisions seem to be driven by an assortment of biases and heuristics — mental rules of thumb that help us get to a reasonable answer if a relatively short amount of time. And these heuristics need not be conscious. Indeed, another relevant trend in psychology has been a greater appreciation of unconscious processes in shaping our decision-making and behaviour. These are not unconscious desires or wishes in the Freudian sense, but processing rules that are not necessarily consciously monitored.

Much of the study of heuristics has highlighted the systematic ways in which human reasoning can veer into illogic. For instance, if you ask people how many words, in four pages of a novel, will have ‘ing’ as an ending, they typically give a higher number as an answer than if you ask how many words will have ‘n’ as the second-to-last letter in four pages from the novel (an example of what is called the availability heuristic, but I won’t go into detail here). And this does not make logical sense.

Similarly, what’s called the ‘representativeness heuristic’ can lead people astray. This is illustrated by looking at people’s answers to questions about the likely career of a hypothetical woman named Linda:

“Linda is 31 years old, single, outspoken, and very bright. She majored in philosophy. As a student, she was deeply concerned with issues of discrimination and social justice and also participated in antinuclear demonstrations.”

After reading this description, people were asked to rank the likelihood of various possible future life outcomes for Linda, the most important two (for the purposes of the study) being ‘bank teller’ and ‘bank teller and active in the feminist movement’. Most people think that the latter possibility is more likely, even though it is statistically more likely that she would be just a bank teller, rather than both a bank teller and a feminist activist. This is known as the conjunction error, in which the occurrence of two independent characteristics is deemed more likely than one alone (and statistics says this isn’t so).

So much for how we actually reason: when it comes to thinking, we’re frequently far from logical. But what about when we put our mind to thinking about a decision or problem? Surely more thinking is better, and more likely to lead to the best solution or choice?

Well not according to some research published in last week’s Science. Ap Dijksterhuis and colleagues at the University of Amsterdam in the Netherlands have found that too much thinking can get in the way of reaching a good decision — perhaps counter-intuitively, this is even more true when the decision is more complex. Conscious deliberation seems to be better suited to making simple decisions, such as what brand of kitchen utensil to buy, but for the more complex and important decisions in life, perhaps such as buying a house or car, less thinking may mean a better decision.

In one set of experiments, participants were provided with a choice of four cars. The task was to pick the best car out of the range on the basis of details about four characteristics of the cars, such as mileage and legroom. Each person had four minutes to mull over the problem, and most participants picked the same car — the one that was in fact best on the basis of the listed attributes. In a variation of this experiment, the cars had 12 characteristics, making the decision-making process more complex because there were more factors to take into account. And this increased complexity of the decision was reflected in people’s choices: after four minutes thought, only 25% picked the car with the best attributes, or no better than merely picking at random. Perhaps understandably, a more difficult choice made for worse decisions.

In the final condition, the participants, after reading about the cars and the 12 attributes, were asked to solve anagrams for four minutes before making their choice of car. And the effect of this distraction? To increase their skill in identifying the best car — after taking their minds off thinking about the car by solving anagrams, more than half of the study subjects picked the best car. This suggests that at least in some cases less explicit, conscious deliberation, and a greater reliance on unconscious mental processes, can help make for better decision-making in complex situations.

Dijksterhuis and colleagues also explored this issue in a more real-life situation: shopping for simple items of clothes and kitchenware, compared with furniture shopping at IKEA (which, being a bigger investment, and relating to home design, can be expected to be a more weighty and complex choice to make). The researchers stopped shoppers leaving IKEA and the shop selling kitchen utensils and other smaller items, and asked them how long they had spent mulling over their decisions. They then called the shoppers up a couple of weeks later to see how happy they were with their purchases. Whereas the people that spent longer thinking the about their small purchases were generally happier with what they had bought, the reverse was true of IKEA shoppers — more thought led to a less satisfactory choice.

One possible reason for the poor performance when making more complicated decisions is that the brain can only keep so much information accessible to consciousness. So perhaps partial or muddled information gets factored into conscious decisions, which then turn out to be bad. This study illustrates that complexity might be a key factor determining whether conscious deliberation or something more gut-based (meaning not consciously thought through, and perhaps emotionally laden) is the most appropriate path to a decision.

But it would be rash to rule out the role of thinking altogether in coming to important decisions. It is quite possible that taking all the relevant information into account, rolling it around in your head for a while, and letting it be unconsciously processed may lead to good decisions. In fact, this is what Daniel Kahneman, a Nobel Prize-winning economist for his work on decision-making, says: “I would not advise people to buy a car or house without making a list. You will probably improve your intuitions by making a list [of pros and cons] and then sleeping on it.” Dijksterhuis agrees: for important decisions, he finds out the relevant facts and focuses his full attention on the decision. Then? “I sit on things and rely on my gut.”

This research might also illuminate the almost magical ability of doctors, fire-fighters and jazz musicians to make accurate on-the-spot decisions about medical care, plans of action, and note choice, for example. It is not that these people are better off for having less knowledge of information with which to consciously work, but that their expert knowledge can be accessed unconsciously and extremely rapidly, through years of experience and practise.

So next time you have a small decision to make, think about for a reasonable time, and go for it; for the bigger ones, have a think, weigh up the options, then think about something else for a while. When you come back to make your decision, it may just make the best choice (or at least one you’ll be happy with).

Wednesday, February 15, 2006

New book: No Two Alike: Human Nature and Human Individuality

A few years back, Judith Rich Harris, a psychology textbook writer unaffiliated with any university, published The Nurture Assumption, which suggested that the home environment provided by parents was of little effect in shaping the personality of their children – genetics, peer-group socialisation, and unique life events play the dominant role. Despite criticism from some quarters, the book was also endorsed by such luminaries as Steve Pinker (who actually wrote a forward to the book).

Now Rich Harris has a new book out, No Two Alike: Human Nature and Human Individuality, in which she apparently outlines a new theory of personality development, one that explains why we — even identical twins — turn out as individuals. The book isn’t available in the UK yet, but in the meantime here’s a review of the book.

Tuesday, February 14, 2006

The Zombic Hunch and the Limits of Thought Experiments

Bring Out Your Dead

Few thought experiments in the philosophy of mind are as popular or famous as the philosopher’s zombie (although John Searle’s Chinese Room probably tops it). These aren’t the cannibalistic, but mercifully slow-walking, corpses of George Romero’s 1978 film Dawn Of The Dead. When philosophers talk about zombies they generally have in mind a being much like me and you in appearance and behaviour — in some instances identical — but lacking any inner mental life, any conscious glow, any feeling of what it is like to experience, say, the scent of a rose or the tang of lemon. But, being behaviourally just like an ordinary human, such a zombie would talk and act just as if they did have conscious experience. Perhaps for all you know me, and everyone other person on the planet, are zombies — it is part of the conception of a zombie that you couldn’t tell by observing our behaviour or by inspecting us physically — that is, the way we act and talk about the world (including our non-existent conscious experience) wouldn’t give our zombiehood away.

Some philosophers have suggested that the possibility, or at least conceivability, of zombies tells us something important about the nature of consciousness and its relation to our physiology, particularly the brain. Others respond that zombies are a confused notion, and have done more harm than good in directing our thoughts about the mind. In the recent book Conversations on Consciousness, Susan Blackmore discusses the possibility and likelihood of zombies with a number of leading philosophers of mind and cognitive scientists, and comparing their accounts can possibly shed some light on what’s going on in the debates.

In discussing zombies with Blackmore, philosopher Ned Block distinguishes between two senses of the philosopher’s zombie, which we might call the ‘functionalist zombie’ and the ‘biological zombie’. I’ll explain both shortly, after a little bit of background on what functionalism is, and the account it gives of the mind (I’ll quote from some good introductory books on the topic that are easily available).

The are many problems in the philosophy of mind, although the problem of consciousness is perhaps currently the most high profile (in the popular mind at least: the past decade has seen a proliferation of popular and semi-popular books on the subject). The are a number of features of mental states we might want to explain: some mental states are caused by states of the world; some mental states cause mental states; some mental states cause other mental states; some mental states are about things in the world; and some kinds of mental states are systematically correlated with certain kinds of brain states (Ravenscroft (2005)).

Functionalism addresses a number of these problems from a perspective that sits well with a materialist conception of the mind, although it is not logically committed to materialism (the idea that everything in the world — mental events and all — have a material, physical basis). In the current climate, in which may if not most philosophers and neuroscientists take the brain to be the material basis of the mind, functionalism has found a welcome home, and has become a major position in the philosophy of mind. However, a wide range of views on the mind–brain relation, and the nature of consciousness, are compatible with materialism, and so functionalism is not the only game in town. However, whatever it’s troubles, functionalism has been an extremely influential approach to the mind, and even its critics take it seriously.

Braddon-Mitchell and Jackson (1996) say “Functionalists take mental states to be the internal causes of behaviour … Mental states are, according to functionalists, internal states within us, but we identify and name them by the effect the world has on them, the effects they have on the world, and the effect they have on the world by causing our behaviour.” Functionalism both helps explain, and derives support from, the fact that mental states can be multiply realised, which means that some states, say pain, can be produced by, or realised in, a number of different physical systems. The possibility of multiple realisation poses problems for theories that identify a given mental state, such as pain, with a certain physical state, such as the firing of C-fibres in the nervous system (although this isn’t neurologically plausible it’s a standard example in the philosophical literature). The claim of the identity theory here is that the firing of C-fibres is identical to being in a state of pain. However, other animals, such as lobsters, seem capable of being in pain states, so an identity theory that identified pain as firing of C-fibres would claim that lobsters must have C-fibres too. But let’s assume that lobsters don’t have C-fibres; they have D-fibres instead. If this is true, then pain can’t merely be the firing of C-fibres. Perhaps we might say that pain is the firing of C- or D-fibres, but then our idea of a mental state is extremely contingent on what we know about nervous systems across the animal kingdom. Functionalism provides an escape from this.

As Ravenscroft (2005) explains, “According to functionalism, C-fiber firing does the same job in me as D-fiber firing does in [lobsters]. On this view, to be in pain is to have an internal state which does a certain job. Which job is that? Very roughly, an internal state does the ‘pain job’ if it is caused by bodily damage and causes us to say ‘ouch’ and rub the sore spot. So according to functionalism, to be in pain is to have an internal state which is activated by bodily damage and which causes us to say ‘ouch’ and rub the sore spot. More generally, according to functionalism, to be in (or have) mental state M is to have an internal state which does the ‘M-job’.” It is important that these functional states have certain causal properties, properties determined by their inputs, how the state responds to the input, its output and its effects on other states of the systems.

Refuting Functionalism?

The idea of multiple realisation is in principle not limited to biological systems as a given functional state can in principle be underpinned by a non-biological machine – a computer, for instance. It has been suggested that a sort of Rube Goldberg device made out of cans, strings and pulleys could, in principle, replicate the functional states of the human brain. An early criticism of the functionalist approach was developed by Block, and is called the China Brain (which inspired the famous Chinese Room). In this thought experiment, everyone in the population of China (assumed to be about a billion, a number much lower, but vaguely in the ball park, of the number of neurons in the human brain) is given a phone. Everyone is also given a set of instructions that say that when a call is received from a given number, or numbers, another call or calls should be made to certain other numbers. In this way, each phone operator is imitating the functional role of an individual neuron.

Now, this is isn’t likely to be set up any time soon, but we can imagine it in principle. So once it was up and running, each phone operator would assume the functional role of a neuron, and collectively they would simulate the functional organisation of the brain. That is, the population would be in the same functional states as a human brain, given the correct inputs and rules of operation. So what if the phone operators were in the same functional state as the brain is when it has a mental state with the content ‘It’s raining’? Would the population of phone operators be in this mental state too? This isn’t about whether individual phone operators would believe that it’s raining, but whether the population of operators are in the functional state of believing that it’s raining – which functionalism is says it is.

It perhaps seems absurd to suppose that the population as a whole is conscious of the belief ‘It’s raining’ in some strange, disembodied state. The existence of a functional state representing the mental belief state ‘It’s raining’ seems insufficient for the conscious awareness of this belief. The problem of consciousness – the first-person perspective on the world, our subjective experience of the world, what it is like to be you, at your computer, as you read this – is indeed a tricky issue for functionalism, as it is for all theories of the mind. But problems in the philosophy of mind are not exhausted by the problem of conscious – in fact, some philosophers, such as Dan Dennett, believe that once the other problems of how the brain/mind works, then the supposed problem of consciousness will disappear. There won’t be an extra ‘something’ to explain when all the other aspects of the mind are explained.

Functionalism fares well in explaining a number of other features of mental states. For instance, it has an explanation of, or at least is compatible with, the following features on mental states that any theory of mind will hopefully address (see Ravenscroft (2005)): some mental states are caused by states of the world; some mental states cause mental states; some mental states cause other mental states; some mental states are about things in the world; and some kinds of mental states are systematically correlated with certain kinds of brain states. It’s not well-suited to explaining the problem of consciousness, as traditionally construed, but does the China Brain thought experiment refute functionalism as an approach to understanding these other aspects of the mind, as it is intended to? It seems perhaps obvious that the China Brain doesn’t have mental states similar in relevant respects to human mental states, but this is an intuition, not an argument, however strong (Braddon-Mitchell and Jackson (1996)).

In any case, Block’s take on the China Brain thought experiment leads him to various conclusions. Block considers functionalism to be insufficient to the task of explaining the phenomenology of mind, and therefore can conceive of a being that is functionally similar to a human, even if physically different from humans, which lacks consciousness. This is a being that is functionally similar to us, like the China Brain was, but which lacks consciousness like the China Brain. This is Block’s notion of what I’ll call a functionalist zombie, and I’ll explore this type of zombie, along with biological zombies, and philosophers’ response to them in the next post.

Zombies And The Philosophers

Ned Block characterises the functionalist zombie as a “person who is functionally like us, but physically so different that this person doesn’t have the physical basis of phenomenology”. He cites the example of a human perhaps made out of silicon chips that were organised to embody functional states identical to those of a human. Block concludes that this being would lack the physical basis of phenomenology, and derives this conclusion from the China Brain thought experiment.

Block also describes a second sort of zombie, what I’m calling a biological zombie:

“The second sort of zombie is a creature that’s physically exactly like us. This is [David] Chalmers’s zombie, so when Chalmers says he believes in the conceivability and therefore the possibility of zombies, he’s talking about that kind of a zombie. My view is that no one who takes the biological basis of consciousness seriously should really believe in that kind of a zombie. I don’t believe in the possibility of that zombie; I believe that the physiology of the human brain determines our phenomenology and so there couldn’t be a creature like that, physically exactly like us, down to every molecule of the brain, just the same but nobody home, no phenomenology. That zombie I don’t believe in, but the functional zombie I do believe in.”

So that’s our starting point: the contrast between functionalist zombies and biological zombies (though this distinction might well be disputed on the grounds that the difference between a functional zombie that behaved intelligently and a creature that behaved in a similarly intelligent fashion but with the boost of consciousness is more imagined than real). Next, here’s how John Searle replies to being asked about zombies by Sue Blackmore, whose reply I’ve included:

“The zombie is really a philosopher’s invention, to imagine a machine or a creature that behaves the same as a person who is conscious but has no consciousness; and I think that makes sense; you can imagine such a thing; I can imagine that you really are a wind up mechanism and that you’re not conscious. It’s a good thought experiment to imagine the differences between ourselves, who have both consciousness and coherent organised behaviour, and the zombie that appears to have the same organised behaviour but does not have any consciousness, has no feelings.”

Blackmore: “Obviously it’s possible to imagine such a zombie, but are you saying that such a zombie could in principle exist?”

Searle: “In principle, sure.”

At first it seems like Searle is just referring to the functionalist conception of a zombie — “a machine or a creature that behaves the same as a person who is conscious but has no consciousness”. But by saying “I can imagine that you are really a wind-up mechanism and that you’re not conscious” he seems to be committing himself to the stronger idea, rejected by Block, of a biological zombie, a creature identical to a human but lacking consciousness. And what could be more identical to Sue Blackmore than the conscious Sue Blackmore? (If he didn’t have this in mind, how could he imagine Blackmore as a zombie, given that she such a zombie would be, in fact, biologically identical to the actual conscious Sue Blackmore? (Of course, we don’t know that Blackmore is really conscious; but Searle is saying that although he thinks that beings of with the kind of biology Blackmore has — humans — are conscious, it’s possible to imagine them as not conscious.) So to take Searle at his word, that he can imagine Blackmore as non-conscious, this strong reading seems fair. The possibility of this biological zombie is often taken to have an important implication: that if we can imagine creatures physically exactly like us, who must definitionally be in identical functional states, then mere functional states are not enough for consciousness. Therefore there is something extra, some special ingredient, that is part of the explanation of consciousness. Blackmore is quick to the chase:

Blackmore: “So as far as you’re concerned, then, there’s something extra; you could have a mechanism that did all this stuff, but it wouldn’t be really like us; it needs something extra, the conscious field or the rational agent or something like that, to make it be like us and have our kind of awareness. Is that what you’re saying?”

Searle: “That’s exactly what I’m saying. I think evolution probably could not have produced such a thing, because evolution produced us. You can imagine evolution producing beings that moved around on wheels instead of on legs; but for all kinds of reasons it’s unlikely that evolution would ever be able to produce that. Similarly, you can imagine evolution producing a well-organised zombie, but it’s unlikely; we just get this much more efficient mechanism if we have consciousness. However, you could, in principle at least, design machinery that could behave as if it were intelligent – that is, could behave in the same way as human beings behave; we’re nowhere near being able to do that, but in principle it’s possible.”

This response muddies the waters a bit in interpreting Searle. He starts by saying that he accepts the conclusion about ‘extra ingredients’ derived from his conception of the zombie thought experiment as discussed Blackmore This suggests that he takes the possibility of biological zombies seriously. This is surprising given the importance Searle places on the brain and its biological functioning in explaining consciousness, which he thinks makes brains conscious, and machines, which don’t have the right arrangement of matter, unconscious.

However, by saying that “I think evolution probably could not have produced such a thing, because evolution produced us”, he seems to suggest something different — at least inadvertently, perhaps. The design process of evolution through natural selection has produced complexly and improbably organised functionally adapted matter — from sub-cellular organelles to organisms — that serves functional ends. Some of this matter is arranged in such a way as to form conscious creatures, like us, and maybe other animals.

I take Searle to believe that the way evolution has operated, and the way it has put physical matter together, entails that consciousness exist. (Not that evolution necessarily entailed the emergence of consciousness, but that given that it put organisms together with our molecular composition, consciousness was inevitable. I say this because Searle believe that the brain in a sense ‘creates’ the mind, that mind is an emergent property of the brain perhaps like wetness is an emergent property of water. Given the molecular structure of water, and the operation of physico-chemical laws, water has the emergent properties associated with being a liquid. In a similar sense, the molecular organisation of the brain (human, at least), operating according to the causal laws of the universe, creates consciousness. Another system made out of different material, say a computer emulating mental processes, would lack consciousness — it hasn’t got the right stuff. This is what I take Searle to mean when he says “I think evolution probably could not have produced such a thing [a mechanism that did all this stuff, but it wouldn’t be really like us], because evolution produced us.”

But then Searle says “you can imagine evolution producing a well-organised zombie, but it’s unlikely; we just get this much more efficient mechanism if we have consciousness. However, you could, in principle at least, design machinery that could behave as if it were intelligent – that is, could behave in the same way as human beings behave; we’re nowhere near being able to that, but in principle it’s possible.” This suggests that Searle now means something else. It seems that he’s now talking about a creature that is not like us molecule for molecule (if it was, it’d be human and conscious). So perhaps Searle means a being potentially quite different from us physically — perhaps a silicon-based life-form, or of just very different biological design — but which was behaviourally similar, one that instantiated the same functional states of a human, but which was a zombie. This, it seems to me, is a rather different claim. On the first reading, it seems that Searle should reject the idea that Blackmore is a zombie, because of his views about the way that consciousness arises from the material composition of the brain. And on the second reading he should reject the possibility too, because he’s supposed to be talking about a functional zombie, which can’t substituted with a biological zombie that Blackmore would have to be if she were any type of zombie! To unpack that a bit, accepting the possibility of a functional zombie doesn’t mean that it’s reasonable to conclude that Blackmore could be a zombie, for if she were to be a zombie she’d have to be a biological zombie, and acceptance of the former doesn’t entail acceptance of the latter.

If this is correct, then the conclusions about the ‘extra ingredient’ needed to explain consciousness don’t follow, and zombies aren’t perhaps so good a thought experiment as Searle thinks.

The next philosopher I want to turn to is David Chalmers, alluded to by Block above and charged with believing in biological zombies. Here’s the relevant dialogue from Conversations On Consciousness (it’s quite long):

Blackmore: “Would you like to explain about zombies?”

Chalmers: “Sure. I think in the actual world, intelligent behaviour and consciousness very likely go together. So when you find a system which is behaving like me and talking like me – it’s probably conscious. But it seems that I could imagine a system which was behaviourally just like me, it walked and talked just like me, it got around its environment, but it didn’t have subjective experience. Everything was dark inside. This would be what philosophers like to call a zombie – a being entirely lacking consciousness.

Now such a being would be tremendously sophisticated. You couldn’t tell the difference from the outside, but there would nobody home inside. Here I am sitting talking to you. All I have access to is your behaviour. Now you seem like a reasonably intelligent human being, you’re saying articulate things that suggest a conscious being inside. But of course, the age-old problem is ‘how do I know?’. It’s at least logically consistent with my evidence that you are a zombie.

Now I don’t think you are, but the very logical possibility of zombies is interesting because then we can raise the question ‘why are we not zombies?’. There could have been a universe of zombies. Think about creating the world. It seems logically within God’s power (and of course the use of ‘God’ here is just a metaphor) to create a world which was physically just like this one with a lot of particles and compelx systems behaving in complex ways, but these were just androids. There was no consciousness at all.

And yet there is consciousness. So that’s been used by some people, including me, to suggest that the existence of consciousness on our world is a further deeper property of the world than its mere physical constitution.”

Chalmers seems to be saying that it’s only something behaviourally like us, not something like us molecule for molecule, that could exist and be lacking in consciousness. When he says “You couldn’t tell the difference from the outside”, he must be interpreted as meaning from a relatively cursory glance of the outside: if outside is taken to mean all types of physical examination and testing, and it’s molecular constitution and physiological operation were found to be identical to that found in humans, then it’d be a human, and we would therefore grant it consciousness (provided we grant the existence of other minds in humans). This gloss is supported by Chalmers’s response to Blackmore’s next question:

Blackmore: “So are you saying that you believe such philosopher’s zombies are possible and the fact that we have consciousness means that we have to add something to the explanation?”

Chalmers: “I think they’re probably not possible in the sense that no such thing could ever exist in this world. I think that even a computer which has really complex intelligent behaviour and functioning would probably be conscious. What is interesting though, is that it doesn’t seem contradictory to suppose, at least in the imagination, that someone, somewhere, in some possible world, could behave like me without consciousness. But our world isn’t like that. So that’s an interesting fact about our world!”

I take Chalmers to be saying that no zombie, in the sense Chalmers intends, could exist in our universe, because of the way it happens to be constructed. But in another possible world, constructed differently, they could. But the possible world Chalmers has in mind cannot be exactly the same as our world – elementary particle for elementary particle, atom for atom, molecule for molecule – as it wouldn’t be an alternative possible world, it’d be our world, which features the very conscious creatures (us) we were trying to imagine didn’t exist!

So Chalmers rejects the possibility of what I called a biological zombie, characterised by Block as “physically exactly like us, down to every molecule of the brain, just the same but nobody home, no phenomenology”. If ‘possible world’ means one that is exactly like our world, then we can ask what it’d mean to imagine such a world containing beings identical to us but without consciousness. It seems akin to saying that you could imagine a world like ours, built from the same elementary particles, fundamental forces and fields, but which didn’t feature mass or electromagnetic radiation or hydrogen. You might be able to say you can imagine such a world, but perhaps your imagination is running away from you there a bit. We might also claim to be able imagine a world identical to this one except that humans can fly by levitation (of course, if it were really identical, we couldn’t, as we don’t); but merely saying this doesn’t then raise interesting questions about why humans, in this world, don’t in fact fly. The mere fact that we think we can imagine this world with something ‘extra’ that enables levitation doesn’t mean that we then have to explain the absence of this ‘extra’ something in this world, or even consider it as a possible ‘extra’ that we could be in possession of. Similarly, the fact that we might — though few do — say that we can imagine identical beings but lacking in conscious, because they lack some mysterious extra ingredient, does not mean that there actually is an ‘extra ingredient’ in our world to explain.

It might be useful here to distinguish between logically possible worlds and nomologically possible worlds, and apply this distinction to the case of zombies. A logical possibility is a state of affairs that doesn’t contradict the laws of logic, and a logically possible world is one the description of which is not self-contradictory. The space of logically possible worlds therefore contains worlds very unlike ours, perhaps where things impossible in our world occur with regularity. A nomological possibility is a possible state of affairs that is consistent with the causal laws of the universe as we know them, and so a nomologically possible world is one that is consistent with the known laws of physics. Under this distinction, levitating humans might be a logical possibility, but they aren’t a nomological possibility. And what does the mere logical possibility of levitation entail for our views about our actual world? Little, in this case. And so why should the logical possibility of zombies be of much relevance to us? The nomological possibility of a zombie would be of interest, but arguing for such a possible being requires a fair bit of work, and is in fact rejected by the philosophers looked at here (with the possible exception of Searle, who seems to drift a bit between the two possibilities, logical and nomological).

Let’s get back to Chalmers. He does not seem to believe in the nomological possibility of what we’ve called a biological zombie, and so Block is wrong to say that this sort of zombie is what Chalmers does in fact believe in. This has implications for what Block claims Chalmers says the implications of zombies are. The sort of zombie Chalmers believes could exist is one that existed in a genuinely alternative possible world, behaved in an intelligent, organised and coherent manner in the pursuit of goals, even reported the possession of conscious experience, but did not have real conscious experience. One, in other words, that had internal functional states that guided intelligent behaviour — Block’s functionalist zombie. Block and Chalmers agree on the nomological possibility of functional zombies and the nomological impossibility of biological zombies. Which prompts Blackmore to ask:

Blackmore: “You say our world isn’t like that. Does this make you a functionalist? Are you saying that, in our world, anything that carries out a certain function must necessarily be conscious?”

Chalmers: “In some very broad sense I am a functionalist. I think that behaviour, and function, and consciousness go together. They are very tightly correlated and associated. But I am not a functionalist in the strong sense of saying that all there is to consciousness is the functioning. So people say that all we have to worry about is functioning and the behaviour and the talking. I think that is just manifestly false because of the direct data of subjective experience. We have correlation of the two without any kind of reduction of one to the other.”

Blackmore: “I want to get this absolutely clear because people talk about your views on zombies a lot. You saying that logically you can conceive of a world in which there would be intelligent-behaving creatures who went around saying like ‘I am conscious’ and ‘I’m experiencing red right now’ and so on, but didn’t have any subjective experience. But you think that in this real world we are in that’s not possible and anything that does these behaviours will necessarily be conscious.”

Chalmers: “That’s exactly right.”

This assent to Blackmore’s presentation of his view reinforces the interpretation of Chalmers’s view that I’ve sketched above. He accepts the nomological possibility of functional zombies, but rejects the nomological possibility of biological zombies.

So far, here’s the tally: Block and Chalmers both accept the nomological possibility of functional zombies, and Searle’s comments suggest that should too, if he’d accept the distinction between functional and biological zombies. Both Block and Chalmers reject the nomological possibility of biological zombies, and therefore reject the conclusions that supposedly follow from their mere conceivability, such as the need to postulate an ‘extra ingredient’ to explain consciousness.

So far one major philosopher has been notable by his absence: Dan Dennett, who doesn’t have much time for considering zombies, driven as it is, he considers, by the ill-founded Zombic Hunch:

“The Zombic hunch is the idea that there could be a being that behaved exactly the way you or I behave, in every regard – it could cry at sad movies, be thrilled by joyous sunsets, enjoy ice cream and the whole thing, and yet not be conscious at all. It would just be a zombie. Now I think that many people are sure that hunch is right, and they don’t know why they’re sure. If you show them the arguments for taking zombies seriously are all flawed, this doesn’t stop them from clinging to the hunch. They’re afraid to let go of it, for fear they’re leaving something deeply important out. And so we get a bifurcation of theorists into those who take the zombic hunch seriously, and those who, like myself, have sort of overcome it. I can feel it, but I just don’t have it anymore.”

I’m not quite sure whether Dennett rejects the nomological possibility of the functional zombie — if it behaved like we did, it’d be conscious like us, perhaps — and I leave that to others to address.

It’s time to summarise. I agree with Dennett that we should let go of the zombic hunch. If you believe in zombies, in the strong, biological, nomological sense, then this should be on the basis of an explicit argument — assent to belief in the possibility of these zombies seems to me more of a conclusion than a starting point for other conclusions to be drawn. As such, asking someone whether they believe in the possibility of zombies (after making sure exactly what you’re talking about!) is a useful diagnostic question in gauging their stance on the mind, but this stance has to be justified by a zombie-independent argument. After all, to avoid circularity you need to provide reasons for concluding that zombies are possible on the basis of your conception of the mind, rather than claiming that zombies are possible, then deriving an account of the mind that explains this possibility — and then using this to explain the possibility of the zombies that motivated your argument!


Blackmore, S. Conversations on Consciousness (Oxford Univ. Press, 2005).

Braddon-Mitchell, D. & Jackson, F. Philosophy of Mind and Cognition (Blackwell, 1996).

Ravenscroft, I. Philosophy of Mind: A Beginner’s Guide (Oxford, 2005).

Sunday, February 05, 2006

Race Reprised, and the Difficulties of Debate

A while ago I posted a on the vexed topic of race, and whether we can talk about race from a genetic perspective, prompted by posts on Mixing Memory and Fido the Yak. My essay wasn’t meant as an attack on MM or Fido, as Chris at MM clearly realised in his reasonable response to my post, but Fido seems to have taken umbrage at what I said – see his response in the comments section of my original post, and in a post on Fido’s blog in which I’m accused of being a racist, despite the fact that I have said nothing to support such an assertion. I want to respond to this unfair and serious charge, and some other issues, and I shall quote from both Fido’s comments on this blog and his own. Apologies if this means going over some familiar ground, and if the tone is somewhat more touchy than usual, but being called a racist is not something I take lightly.

In the comments section, Fido says:
If I believed Pinker meant to talk about human groups in way consistent with the groupings RPM [a blogger who commented on my original post, D.J.] points to, I would still say he is a racist, but I would be inclined to admit that the word could be taken in a less perjorative sense than is commonly understood.
Why would RPM’s groupings (and RPM has blogged on the reality of race here [D.J. I made an error here - it was someone else blogging on GeneExpression that wrote the post, sorry]), if adopted by Pinker, lead Fido to conclude that Pinker is a racist? Fido hasn’t provided any evidence that Pinker is a racist, and I think it’s an absurd claim — for the third time Fido, please back this charge up. And in response to my comments about finding support for Pinker’s use of the notion of race, Fido writes:
I don't understand who's supposed to be a contrarian fringe expert in this discussion. Cavalli-Sforza's vita and list of publications is quite impressive to me, though he has not to my knowledge published in Daedalus, and I am myself a contrarian fringe dilletante. So a big grain of salt there.
Well done Fido on being a “contrarian fringe dilettante”, that’s marvellous. However, I take responsibility for inducing this tone in Fido, because I omitted a crucial word in my parenthetical comment in the original post: ‘not’. So a crucial sentence should have read “But it doesn’t take much searching to challenge this idea (and NOT through selective picking of contrarian, fringe experts)…”), and I apologise for misleading readers, including Fido (who may have taken me to be implying that Fido was selecting fringe experts, which I was not). I meant to say that it was possible to challenge Fido’s comments about race, and indeed the AAA’s and AAPA’s, without resorting to quoting fringe experts, as the Republican party tends to do with the science of global warming (see Chris Mooney’s The Republican War On Science for more). The geneticists that work on the ancestry of human genes, their distribution across the globe and their clustering into geographic populations often have something to say that differs from what anthropologists might say (and I think this is part because of the different intellectual traditions of the respective disciplines, but I can happily let that slide for the moment). I agree that Cavalli-Sforza has an impressive research record, but there’s an irony in bringing him up again.

Cavalli-Sforza, as Fido no doubt knows, has said that “The classification into races has proved to be a futile exercise”, so here’s an agreed authority supporting Fido’s view. Presumably Fido wouldn’t classify him as a racist too, right? Interestingly, Cavalli-Sforza was also one of the lead proponents of the Human Genome Diversity Project, intended to catalogue at least some of the nature of human genetic diversity. And what happened to this project? Well, luckily a book has been written on this topic (Race to the Finish: Identity and Governance in an Age of Genomics, by Jenny Reardon, reviewed in Nature). Here are some quotes from the Nature review:
“The Human Genome Diversity Project had a short and troubled life. The aim was to sample and preserve DNA from “isolated indigenous populations” before social changes rendered them useless for the purposes of answering questions about human evolution. But from its birth around 1991 to its unofficial death less than a decade later, indigenous-rights groups attacked the project as racist and neo-colonialist, branding it the ‘Vampire Project’ … Today research on human genetic variation flourishes, but under other rubrics and largely under the radar of Diversity Project critics.

As Jenny Reardon stresses in her book Race to the Finish, the project’s leaders were well-intentioned and had impeccable anti-racist credentials. So why did their effort draw unremitting hostility from groups representing indigenous peoples, some physical anthropologists and others? And could critics’ fears have been allayed without gutting the project? … To be tarnished with the brush of racism — especially given their personal histories — much have been galling. Luigi Luca Cavalli-Sforza had been a trenchant critic of William Shockley’s claim of black genetic inferiority; Robert Cook-Deegan had a long record of involvement with Physicians for Human Rights; and Mary Claire King had worked with the grandmothers of the Plaza de Mayo to identify children kidnapped during Argentina’s dirty war. But avowals of their good intentions did not mollify critics, and organizers eventually set about addressing specific concerns.” [action which was attacked along similar lines]
After some more history, the review concludes:
“The study of human genetic variation is now fashionable, but it is being pursued without the scrutiny of the deeper issues that Reardon believes essential to the pursuit of both a more reflective science and a more sensitive society. Funders have understandably tried to avoid the controversies that sank the Diversity Project. But the ironic result has been to narrow discussion of the issues at stake even further.”
It wasn’t actual racism that created fear and anger in the critics of the Diversity Project, nor a deep engagement with the underlying science, but misplaced concerns about what the project meant and would claim about human nature. Can Fido in good conscience really say that there aren’t reflections of these problems in our discussion? Physical anthropologists, one of Fido’s prosecution witnesses, are explicitly mentioned here, and not by chance either. Because of the history of the discipline of anthropology, anthropologists of many stripes have approached certain topics in certain ways, which have arguably been influenced by politically or ideologically motivated ideas about human nature, which I’ll come back to later.

There is a final twist in the story of Cavalli-Sforza. On the front of one his major books, there is a map of genetic groups derived from the sort of work Cavalli-Sforza has pioneered — a grouping that looks very much like the sorts of groups formed when you analyse genetic lineages on the basis of common heritage, which will often have a geographical correlate — the clustering of geographical variants that we’ve been discussing. Jonathan Marks, one of the panellists on the SSRC’s ‘Is Race Real?’ forum, cited favourably by Fido, has pointed out an irony in this (see also other pages on Marks’ site for criticisms of the Diversity Project, such as the charge that “The images it conveyed were colonialist, exploitative, and racialized”):

“The HGDP says that one of its aims is to show that "... in biological terms, there is no such thing as a clearly defined race.... Most importantly, therefore the results of the Project are expected to undermine the popular belief that there are clearly defined races, [and] to contribute to the elimination of racism...."
This quotation is from their summary document, on the web at:

And yet their literature has shown this figure [see map at top of blog] several times, with the caption “Four major ethnic regions are shown. Africans are yellow, Australians red, [Mongoloids blue], and Caucasoids green.” See, for example, The History and Geography of Human Genes, by Cavalli-Sforza, Menozzi, and Piazza (Princeton University Press, 1995).”
So although Cavalli-Sforza has publicly rejected the notion of race, and Fido seems friendly to his analysis of human genetic variation, Cavalli-Sforza also seems to invoke genetic clusterings of the sort I’ve been alluding to, as Marks points out. Nwo there are obviously a number of ways to respond to this. Firstly, we could say that Cavalli-Sforza was being disingenuous, that he knew that he believed in race but publicly pretended he didn’t so as to avoid disapproval. Or we might more realistically say that although he rejected the usefulness of specific racial classifications, such as those commonly used in the US and Europe, he had a use for the notion of geographical variants (or human groups classified on the basis of common heritage, which will often have a geographical correlate), and just preferred not to call them races (even though this might go against the traditional use of race in evolutionary biology and taxonomy). So where does Fido now stand in relation to Cavalli-Sforza? Is he in the fold, or does he get kicked out for being a racist?

Fido’s blog makes some other different points:
When I included in Under the Sun a link to the Social Science Research Council's online forum Is Race Real?, it occurred to me that it would not do the job I wanted it do, namely, pass the question of "race" over to experts in the scientific study of human biological diversity. Now that blogger Dan Jones has taken issue with my post, I feel compelled to reiterate the distinction between Richard Lewontin's political beliefs on the one hand, and the scientific consensus that has built up around the question of "race" on the other. To that end, I now cite the American Anthropological Association's Statement on "Race", their Statement on "Race" and Intelligence, and the American Association of Physical Anthropologists' Statement on the Biological Aspects of Race. I stand by my claim that the consensus opinion among scientists is that race is "not a useful scientific concept. It doesn't describe observable human genetic variation with adequate precision, and it typically introduces more problems than it solves."
There are a number of points to reply to here. Fido suggests that Lewontin’s political beliefs (and I presume by extension those of other scientists) are separate from the scientific claims made about race, or are at least separable. Of course, this is how it should be, but I think it can certainly be contested that scientists’ views on issues as broad as human nature in general (including, but not exhausted by, such fields as behavioural genetics and evolutionary psychology) and specific topics such as sex differences and the concept of race have historically been so separate (and in both directions; people have erroneously asserted that there is a scientific justification for racism or other forms of discrimination and prejudice – think Social Darwinism). Many responses to these sorts of topics have been motivated by sincerely held and entirely understandable social and political concerns, as (not exclusively) documented by Steven Pinker in The Blank Slate (I don’t expect Fido to accept Pinker’s analysis, and I don’t expect that I could convince Fido either). Historically anthropologists have stressed the biological similarity of humans, which means that the variability of humans is to be explained in cultural terms, thus fitting in nicely with a blank slate, or nuturist, view of human nature, one that stresses the malleability of the human mind and behaviour, and our freedom from the constraints of biology. Of course, there is something in this, but I think there has been a tendency for sensitivity about discussing the biological basis of human differences, or the idea of such differences per se (whether related to sex or race or whatever), to cloud discussions of a number of important topics. Again, I don’t expect Fido to agree, and I can live with that (without further conversations we’ll have to agree to disagree for the time being), but I can’t live with being labelled a racist. Sociobiology was labelled as inherently racist and right wing, and E. O. Wilson was linked to eugenic and Nazi policies — these responses suggest less of an engagement with the arguments and more a loading of the topic with associations it shouldn’t, or needn’t, have.

Moving on to the statements from the AAA and AAPA, I also have a few remarks. Firstly, they’re from 1998 and 1996, respectively. That doesn’t make them wrong, of course, but it does mean that they do not take into account the explosion in genetics and genomics that has occurred in the intervening 8-10 years. Surely it is possible that their comments might need to be revised in the light of new evidence or new analytical tools (except of course if we rule of the possibility of race having a reality a priori, in which case why bother with an argument at all?). If we take race to mean not the racial classifications of any particular culture, but use it in a weaker sense, as denoting populations (that may be more or less geographical linked) that cluster genetically on the basis of common heritage, but not discretely, then what is Fido’s objection to the notion of race (or geographical variants for short — I assume we’re talking about the concept and not merely the name)? Is Fido claiming that the results summarised in the Scientific American article (which I cited because it’s easy to access, and accessible for other readers, as with the Daedalus essays) are just wrong? Sure, the genetic clusterings described in the SA article don’t fit neatly onto the racial classifications commonly used in the West, but that doesn’t mean we can’t talk about them as races (or geographic variants). Of if Fido thinks that it does, can Fido explain why, and why evolutionary biologists have been mistaken in using this term, interchangeably with geographic variants, in their work.

In any case, I don’t see how citing the AAA’s and AAPA’s conclusion, which is all Fido does, shows how these scientific conclusions are untainted by social or political ideology. What it shows is the public face presented by a professional scientific organisation (and I’m not implying that the public face is necessarily different from the private one), a point I’ll return to below.

In the comments section on my blog, Fido says:
It was a mistake, I now realize, to assume that people who read my blog and genuinely cared about the scientific description of human genetic diversity would be familiar, or have the ability and the gumption to make themselves familiar, with the American Antrhopological Association's Statement on "Race", and their Statement on "Race" and Intelligence, or the American Association of Physical Anthropologists' Statement on the Biological Aspects of Race.
Fido goes on to quote some of the AAA’s and AAPA’s statements:
“Pure races, in the sense of genetically homogenous populations, do not exist in the human species today, nor is there any evidence that they have ever existed in the past” Further, the AAPA states, "There is no necessary concordance between biological characteristics and culturally defined groups. On every continent, there are diverse populations that differ in language, economy, and culture. There is no national, religious, linguistic or cultural group or economic class that constitutes a race. However, human beings who speak the same language and share the same culture frequently select each other as mates, with the result that there is often some degree of correspondence between the distribution of physical traits on the one hand and that of linguistic and cultural traits on the other. But there is no causal linkage between these physical and behavioral traits, and therefore it is not justifiable to attribute cultural characteristics to genetic inheritance." That is the consensus opinion of scientists who specialize in the study of human physical diversity. I have no wish to imply that the weight of expert opinion refutes Pinker; I mean to state it flat out.
Well, I agree with the first quote, as would Pinker and as would the geneticists I’ve been quoting in support of my position. So what’s its relevance? We’re talking about a subtler notion of race amenable to a type of analyses that wouldn’t have been possible when the AAA and AAPA statements were made. The second long quote is largely irrelevant, as accepting the claims of the geneticists I quoted does not entail any of the conclusions rejected in that quote. Talk about attacking straw men! Fido goes on:
As an aside, I repeat my view that the conventional wisdom among scientists is open to revision. It is not my intention to represent the scientific consensus as monolithic, dogmatic or otherwise etched in stone. My criticism is with the way Pinker and Leroi have gone about attacking the conventional wisdom. Strawman arguments and appeals to common sense racism do not cut it in my book.

One of Mr. Jones' more curious objections, indeed it may the substantive thrust of his post, is that reasonable people ought to "be able to discuss the science of race sensibly, without racist connotations." There is in fact no "science of race" among the modern sciences, but rather sciences of genomics, human population genetics, physical anthropology, and so on. However, if one wishes to buck the conventional wisdom by holding on to the claim that races exist and ought to be studied scientifically, then one is a racist by definition, a "scientific racist" to be precise. If you take that position, and the connotations of the word "racist" bother you, then you might take that as an indication that there's a problem with your choice of words. I certainly don't have the power to change connotative meanings, or to redefine "racism" to not mean "racism," and I don't have any solutions for those who want to be racists without being "racists." It's just not my cup of tea.
So if I don’t like the idea of being a racist, then I shouldn’t use the word race, because to use the concept/word race means that I’m automatically a racist? Is this for real? So if I believe that there are two sexes, then I must be a sexist, because believing in two sexes necessarily makes me a sexist? This is barmy.

Fido claims that the scientific consensus is that race is not a useful scientific concept (well it depends on your interests, obviously – it was scientifically useful in getting the drug BiDil approved by the FDA, regardless of whether the use of race was a proxy for a genetic or environmental basis of the different efficacy of the drug in self-identified blacks and whites). Fido also claims that if you do believe in race, in the weaker sense above, then you’re de facto a racist (with or without the modifier ‘scientific’). This is ludicrous, and suggests the sort of knee-jerk reaction that often goes with discussions of sensitive topics surrounding human nature (see
The Blank Slate for a detailed history of such reactions). To be racist is, according to standard usage, to think that race is a primary determinant of physical and character traits (nothing I or Pinker or the scientists I discussed imply or endorse), or that some racial characteristics make some races inherently superior to other races; or to be prejudiced against people or groups on the basis of their race. Nothing that I’ve said makes me a racist in any of these senses, and if by scientific racist Fido means that I’m not merely a racist on the grounds of faith, but because of my faulty reading of the scientific literature, then Fido is way out of line. I’m not a racist in any sense, period, and Fido should exercise a little care and caution in bandying these terms about. And I don’t see the point of the stuff about connotative meanings, apart from as an exercise in sarcasm. If I don’t like the connotation of being a racist, don’t use the word race? If you don’t like the connotation of being a sexist, don’t use the word sex? And you don’t need to change word meanings, you just need to understand what the words mean. And finally, the implication that I want to be a racist without being called a “racist” is just way off the mark, as should hopefully be obvious by now — there is nothing that I’ve said that makes me a racist! If it’s not your cup of tea Fido, stop drinking, and don’t pour out cups for others!

And I think Fido is being disingenuous in saying:
“One of Mr. Jones' more curious objections, indeed it may the substantive thrust of his post, is that reasonable people ought to “be able to discuss the science of race sensibly, without racist connotations.” There is in fact no “science of race” among the modern sciences, but rather sciences of genomics, human population genetics, physical anthropology, and so on.”
I would’ve thought it was obvious I was using ‘the science of race’ as a rubric to cover those fields of study that are relevant to discussions of race. Fido is basically saying, “There is no such thing as race, and therefore there couldn’t be a study of it!” — this is the natural interpretation of the point of saying that there is no science of race on the basis of believing that race isn’t a real thing and that there is no scientific concept of race. Yet this begs the question of the validity of the race concept (more or less carefully defined) — and the scientists and work I alluded to are a challenge to this claim. Yes, the AAA and the AAPA have dismissed some ideas about race, but what they say doesn’t seem to affect the ideas and results I was trying to talk about — that is, these results don’t purport to assert what it is the AAA and AAPA wish to deny! The claims of the AAA and AAPA statements are quite broad, and so it is possible to agree with their broad conclusions and still continue to study races (or human groups classified on the basis of common heritage, which will often have a geographical correlate) in scientific terms. You can agree with the AAA and the AAPA, and also take into the account the research I mention — and not be a racist either.

So I ask Fido the following:

· To show that the results summarised in the Scientific American article are either invalid or to explain why can’t we use “genetic information be used to distinguish human groups having a common heritage and to assign individuals to particular ones”, what we might call races following evolutionary and taxonomical practice ‘races’ (or geographical variants – and if Fido is happy with geographic variants, but just doesn’t like the term race because it’ll make people think of the standard racial classifications, then can Fido explain why we’ve wasted so much time when Fido could have said, “OK, that sense of race is OK, but let’s not call it race”. I might well be persuaded with that line, and I think if I ever discuss race again I’ll define race as above and make sure it’s clear that this term is shorthand for this more subtle sense).

· To substantiate the claim that Pinker is a racist, that I am a racist, and that RPM is a racist.

That about wraps it up. I don’t expect that Fido will agree with much of what I’ve said, but it’s a shot at setting the record straight about whether my discussion of race makes me a racist or not, and what it means for others to talk about race, and why it’s still such a difficult notion to discuss.


After writing this reply I came across another set of comments from Fido. There have been four in total: the original post on Fido’s blog; the reply in the comments section of my blog; in the second post on Fido’s blog; and the final set, which I came across late, which are a response to my announcing that I had written a post related to Fido’s original post! It’s the last set I’m replying to here:

Fido starts:
The point that interests me about Pinker's statement, and that prompted me to post "Under the Sun," is not the debate about how best to characterize human genetic diversity. My concern really is the suggestion that somebody's claim a to a common sense view of race should in any fashion serve as a rebutal to conventional wisdom among scientists. This is not to say that the consensus opinion of scientists is beyond critique, or that there aren't important disagreements in the area of human population genetics. I have already indicated that I believe the conventional wisdom is open to revision. My argument is that appeals to common sense are not appropriate in this context.

There is a question of expertise here, and if you were to argue that Pinker's expertise cannot be judged on the basis of this one statement or any excerpt from it, I would cede that point. And the question of whether Pinker routinely speaks authoritatively outside his area of expertise I would agree to set aside for the time being. There remains a curious argument about common sense and conventional wisdom which Leroi has put forward and Pinker has chosen to cite.

The argument about the strawman fallacy is key. Are we talking about "conventional wisdom," "Lewontin's opinion," or, in your words, the opinions of "Lewontin and company"? I cite the AAA and AAPA as additional authorities, if any were needed. On the matter of "race," the opinion ascribed to "Lewontin and company" rather represent the consensus view of scientists. If you think that the dominance of this view represents a case of ideological hoodwinkery rather than the product of decades of scientific study, I feel that the onus is on you to make the case. So I think I have done what I need to show that the "conventional wisdom" really is the "conventional wisdom," and that's all that I need to do to talk about the things that interest me.
OK, let’s start with what Fido originally said (in the first post on the topic):
“Steven Pinker's most dangerous idea is that "Groups of people may differ genetically in their average talents and temperaments." It's not the sort of thing I'd have much to say about--when I want to learn about population genetics, I consult a population geneticist, Luigi Luca Cavalli-Sforza, for instance, who would give me plenty of reasons to doubt that what Pinker says approximates anything I should pay attention to. But Pinker did make one interesting comment, and the fact that I believe he's a sexist, a racist and willfully ignorant of certain facts of evolutionary science shouldn't blind me to the possibility that he may have stumbled over an interesting idea. Pinker writes:

In March, developmental biologist Armand Leroi published an op-ed in the New York Times rebutting the conventional wisdom that race does not exist. (The conventional wisdom is coming to be known as Lewontin's Fallacy: that because most genes may be found in all human groups, the groups don't differ at all. But patterns of correlation among genes do differ between groups, and different clusters of correlated genes correspond well to the major races labeled by common sense.)

Where to begin? I'm most interested in the contrast Pinker sets up between "conventional wisdom" and "common sense," but I must observe in passing that Leroi's op-ed and Pinker's abridged version of it represents a sterling example of the error in reasoning known as the straw man fallacy. Critical responses to Leroi can be found in this collection of essays put together by the Social Science Research Council.”

Anyway, what's this business about going against conventional wisdom in favor of common sense? Is that particularly scientific, or even reasonable? Common sense tells us that the sun rises in the East and sets in the West. Conventional wisdom among astronomers, at least since Copernicus, is that the earth orbits the sun while rotating on its axis once every twenty-four hours or so (a period astronomers call "mean solar time"--go figure). The common sense view of sunrises and sunsets is not invalidated by conventional astronomical wisdom, although with advances in technology, we see that it in some regards common sense, like conventional wisdom, is open to revision.
The quote from Pinker doesn’t show that he’s going against the conventional wisdom simply motivated by common sense, or that he sets up a contrast between them (it could be read into the quote I suppose). He’s making three claims: one, that a conventional wisdom has emerged that race does not exist; two, “that patterns of correlation among genes do differ between groups”; and third, that “different clusters of correlated genes correspond well to the major races labeled by common sense”. It’s not because it’s common sense that it is opposed to the conventional wisdom, but just that the common sense idea happens to stand in opposition to the conventional wisdom.

Now I’ll be honest, I’m not particularly keen on the wording of Pinker’s quotation, and I don’t see why he needed to mention common sense at all, but that doesn’t mean I endorse Fido’s response either. The key points are that there is a scientifically defensible conception of race, and it doesn’t entail the racism Fido assumes it does.

Let’s get on to the strawman fallacy – that Pinker and Leroi are creating an imaginary foe. The targets of their comments about race are those who believe that race doesn’t exist, or that it is a useless concept and entails racism. Do such people exist? Yes, and include Fido, Lewontin, and the AAA and AAPA that Fido endorses – indeed, it is in citing these authorities that Fido says the refutation of Pinker “is the consensus opinion of scientists who specialize in the study of human physical diversity. I have no wish to imply that the weight of expert opinion refutes Pinker; I mean to state it flat out.” What Pinker means by conventional wisdom, and what Fido means by scientific consensus, are the same thing, and they both agree on what it says – that what the conventional wisdom/scientific consensus says about race conflicts with what Pinker/Leroi (and Mayr, Crow, Olson + Bamshad and many others) say about race – which is why there’s a debate (which Fido would like to end as a non-debate, because there is “no science of race”). Contrary to what Fido says, what is interesting about this debate is not the supposed contrast between “conventional wisdom” and “common sense”, but who is right about the nature of human genetic variation, and what this means in understanding human diversity – because there is no pitching of common sense against conventional wisdom. What on earth is the confusion about then?

I’m really at a loss as to why Fido’s “concern really is the suggestion that somebody's claim a to a common sense view of race should in any fashion serve as a rebutal to conventional wisdom among scientists” – Pinker did not advance this notion, and so it didn’t need addressing: to repeat, to say that scientific evidence refutes a conventional wisdom (one that denies something obvious to common sense) does not mean that you are saying common sense refutes or rebuts the conventional wisdom by some inherent superiority of common sense; it merely means that the rebuttal of the conventional wisdom by scientific evidence serves to reinforce common sense. It could easily go the other way (you could have a conventional wisdom that was in line with common sense, and then scientific evidence could undermine both). And lest I be misunderstood again, I’m not actually suggesting that scientific results completely support our common sense notions of race, whatever they are (as I said, in this case I’m not keen on the wording, although common sense isn’t strictly banned from my lexicon). I’m just responding to the claim that Pinker is setting up conventional wisdom against common sense.

And so the really interesting question is whether the scientific evidence and the conventional wisdom clash, and this is what Pinker, Leroi, myself, PRM and others have tried to talk about. Whether it not

Finally, when I wrote "I believe he's a sexist, a racist and willfully ignorant of certain facts of evolutionary science" (in a dependent clause, no less) I deliberately used the phrase "I believe" because I didn't particularly feel like carefully substantiating what in fact are my beliefs. We could examine my beliefs about Pinker, if you would like, but I think it's fair to say upfront that I recognize no professional or bloggerly obligation to be nice to Pinker, and my sensibilities about words like "racist" are decidedly not British.

This is an outrageous get-out clause “I can say what I like and you can’t ask me to justify what I say if I add ‘I believe’ before the claim”. To quote Fido, where to start? For a kick off, adding that your belief something that you express doesn’t diminish your commitment to it, or signify that you won’t offer reasons to make the claim and for which you assent belief in it, or that the belief is held in the absence of reasons (if it is this should be made clear so people know what they’re dealing with). And what is a belief other than something that you feel you can publicly justify, and that you have reasons for holding (otherwise why would you bother assenting belief in it?)? Beliefs are, or should be, those things we adduce reasons to hold — unless of course you think it’s OK to hold serious beliefs on some non-evidentiary basis. And what are we to make of the claim that Fido doesn’t “particularly feel like carefully substantiating what in fact are my beliefs” when it comes to a belief about something as serious as whether an influential public intellectual is a sexist or a racist? Why bring it up in a public forum if you’re not really interested in defending this position, and why think it isn’t incumbent on you to defend this claim? It seems a remarkable stance to take, and a flippant one to boot. And moving on to beliefs more generally, do you not feel like substantiating your belief in, say, evolution (if you believe that evolution has happened on earth, that is), merely because it’s a belief? Or is this not just a belief, however justified by reasons and evidence — do you have some sort of direct line to the truth, so that whereas you only ‘believe’ some things others you actually ‘know’, and the latter you’ll bother to defend? I assume Fido is making reference to a distinction between belief and knowledge, but the difference surely isn’t between having reasons on the one hand (in the case of knowledge) and not on the other (belief, which therefore doesn’t need substantiating) – reasons are crucial to both, and in fact claims to knowledge normally do not signify certainty, but belief held with a high degree of probability of being true because of the strength of the evidence and arguments in its favour. So it’s no good to say, “This is what I believe, and this is a serious charge against another person, but I have no obligation to carefully substantiate my claim because it is, after all, only a belief”. Fido, your blog is full of your beliefs – can we assume that you’re not really bothered to substantiate what you say on it because they are just that, beliefs? Can we take them with the big grain of salt you alluded to in response to my post?

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