Picture: Theory theory vs simulation theory. Mitchell Herschbach spoke up for folk psychology in the JCS recently, suggesting that while there was truth in what its critics had said, it could not be dispensed with altogether.

What is folk psychology anyway? It is widely accepted that one of our basic mental faculties is the ability to understand other people – to attribute motives and feelings to them and change our own behaviour accordingly. One of the recognised stages of child development is the dawning recognition that other people may not know what we know, and may believe something different. There is relatively little evidence of this ability in other animals, although I believe chimps. for example, have been known to keep their discovery of food quiet if they thought other chimps couldn’t see it. Commonly this ability to understand others is attributed to the possession of a ‘theory of mind’, or to the application of ‘folk psychology’, a set of commonsensical or intuitive rules about how people think and how it affects their likely behaviour.

So far as I’m aware, no-one has managed to set out exactly what ‘folk psychology’ amounts to. An interesting comparison would be the attempt some years ago to define folk physics, or ‘naive physics’ as it was called – it was thought that artificial intelligence might benefit from being taught to think the way human beings think about the real world, ie in mainly pre-Newtonian if not pre-Galilean terms.  It proved easy enough to lay down a few of the laws of folk physics – bodies in motion tend to slow down and stop; heavy things fall faster than light ones – but the elaboration of the theory ran into the sand for two reasons; the folk-theory couldn’t really be made to work as a deductive system, and as it developed it became increasingly complex and strange, until the claim that it resembled our intuitive beliefs became rather hard to accept. I imagine a comprehensive account of folk psychology might run into similar problems.

Of course, ‘folk psychology’ could take various forms besides a rigorously stated axiomatic deductive system.Herschbach explains that one of main divisions in the folk psychology camp is between the champions of theory theory (ie the idea that we really do use something relatively formal resembling a scientific theory) and simulation theory (you guessed it, the idea that we use a simulation of other people’s thought processes instead). Some of course, are attracted by the idea that mirror neurons, those interesting cells that fire both when we perform action A and when we see action A performed by someone else, might have a role in providing a faculty of empathy which underpins our understanding of others.  According to Herschbach the theory theorists and the simulation theorists have tended to draw together more recently, with most people accepting that the mind makes some use of both approaches.

However, the folk folk face a formidable enemy and a more fundamental attack. The ‘phenomenological’ critics of folk psychology think the whole enterprise is misguided; in order to guess what other people will do, we don’t need to go through the rigmarole of examining their behaviour, consulting a theory and working out what their inward mental states are likely to be, then using the same theory to extrapolate what they are likely to do. We can deal with people quite competently without ever having to consider explicitly what their inner thoughts might be. Instead we can use ‘online’ intelligence, the sort of unreflecting, immediate understanding of life which governs most of our everyday behaviour.

The classical way of investigating the ‘folk psychology’ of children involves false-belief experiments. An experimenter places a toy in box a in full view of the child and an accomplice. The accomplice leaves the room and the experimenter moves the toy to box b. Then the child is asked where the accomplice will look for the toy. Younger children expect the accomplice to look for the toy where it actually is, in box b; when they get a little older they realise that the accomplice didn’t see the transfer and therefore can be expected to have the false belief that the toy is still in box a. The child has demonstrated its ability to understand that other people have different beliefs which may affect their behaviour. Variations on this kind of test have been in use since Piaget at least.

Ha! say the critics, but what’s going on here besides the main show? In addition to watching the accomplice and the toy, the child is going through complex interactions with the experimenter – obeying instructions, replying to questions and so on. Yet it would be absurd to maintain that they are carefully deducing the experimenter’s state of mind at every stage. They just do as they’re told. But if they can do all that without a theory of mind, why do they need one for the experiment? They just realise that people tend to look for things where they saw them last, without any nonsense about mental states.

Herschbach accepts that the case for ‘online’ understanding is good, but he thinks, briefly, that the opponents of folk psychology don’t give sufficient attention to the real point of false-belief experiments. It may be that we don’t have to retreat into self-conscious offline meditation to deal with false beliefs, but isn’t it the case that online thinking is itself mentalistic to a degree?

It does seem unlikely that beliefs about other people’s beliefs can be banished altogether from our account of how we deal with each other. In fact, our tendency to attribute beliefs to people by way of explanation is so strong we automatically do it even with inanimate objects which we know quite well have no beliefs at all (“MS Word has some weird ideas about grammar”).

The problem, I think, is not that Herschbach is wrong, but that we seem to have ended up with a bit of a mess. In dealing with other people we may or may not use online or offline reasoning or some mixture of the two; our thinking may or may not be mentalistic in some degree, and it may or may not rely on a theory or a simulation or both. The brain is, of course, under no obligation to provide us with a simple, single module for dealing with people, but this tangle of possibilities seems so complicated we don’t really seem to be left with any reliable insight at the end of it. Any mental faculty or way of thinking may, in an unpredicatble host of different ways, be relevant to the way we understand each other. Alas (alas for philosophy of mind, anyway), I think that’s probably the truth.


  1. 1. Lloyd Rice says:

    You want a comprehensive theory. No room for slipperiness?

  2. 2. Lloyd Rice says:

    Sorry. Didn’t mean to be flippant. I banged out my reply before I read your last paragraph. I vote for some sort of messy combination of a sort-of folk psychology, not detailed enough to be refuted, mirror neurons which don’t quite do all they’re cracked up to do, and maybe (for the babies) the beginnings of rational thought. And I see no reason to believe that everybody does it the same way.

  3. 3. Paul Bello says:

    Perhaps I’m misunderstanding the difference between the “phenomenological approach” and the simulation theory. One of the main difficulties in assessing any claims about ascription of mental states (to self or other) is that almost every major theoretical approach is sorely lacking in formal detail. A few of us are working on implementations of computational cognitive architectures capable of ascribing (some) mental states in the context of performing perspective-taking and false-belief tasks. As far as I can tell, there are more than one approach to mental simulation — both offline (as you’ve described it) and online (mostly championed by Robert Gordon). Online simulation seems to have the same sorts of qualities as the so-called “phenomenological” or eliminativist approach you mention.

    I think in the abstract, you are right — mental state attribution cannot be computationally characterized as purely theory or purely simulation. Given the sheer volume of simulation required to participate in even the simplest dialogue, or in recognizing intentions in the routine actions of your coworkers, friends and family, it seems that at the least, simulations must be stored and possibly reified in the service of theory-driven inferences. But attribution of default beliefs to agents we’ve never encountered before, and the profound evidence for shared self-other neural circuitry in service of empathy *and* recognition of intention-in-action (grasps, reaches, etc) speaks against a purely theory-based approach.

  4. 4. Peter says:

    No need to apologise, Lloyd. Actually yes, I do want a comprehensive and unslippery theory, but I realise I’m not going to get one!

    Thanks, Paul. If I’ve understood him correctly Herschbach believes the people he puts into the phenomenological camp would rule out simulation, believing that we understand the behaviour of other people without running any kind of model. Whether this is plausible may depend on what you understand by a ‘simulation’. You say, pertinently, ‘every major theoretical approach is sorely lacking in formal detail’ – yes, indeed. The formal details are where it gets tough (but surely also where big rewards might be found). I salute what you’re doing in this respect.

    Drawn at its broadest, I reckon the task of understanding each other is one of the hardest we face, and it’s likely that all our mental faculties are called for in dauntingly complicated combinations.

  5. 5. Paul Bello says:

    Thanks Peter,
    I’m noncommital about whether such simulations are entirely consciously accessible. At least from the standpoint of empathy, disgust, fear-response, and other “low-level” cognitive phenomena, the neuroscience and psychology suggests that our conscious feelings/judgments about others largely stems from unconscious assessments of self-other similarity, etc. So I’m not sure what Herschbach means when he says someone “runs a model.” This sort of statement entails some sort of intentional choice to simulate, which again, I’m unclear about. Thus my willingness to consider his phenomenological camp a member of the set of online simulation theories stems from the possibility that online simulation is largely automatic and often unconsious.

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