We consume a lot of information these days about psychology and neuroscience. Daily papers and popular magazines almost always include the results of some study or other, that give us further insights into the way humans are – what our motivations are, how we process information, the effects of our emotional states and so on. Underlying all of these bits of information though, is an important theoretical distinction between two different kinds of thinking about people. At a basic level, these are the physicalist/materialist way of thinking about people, and something I will call (as most Philosophers do) ‘Folk Psychology‘.
Physicalist ways of thinking about people, and minds, include neuroscience. Whenever we hear about studies that say something like ‘new research into such and such a brain area shows that teenagers can’t help being rude’ this is a physicalist way of describing people. It doesn’t refer to any internal mental states really, and rather describes human behaviour as being driven by electro-chemical events in the brain and nervous system. This way of describing people and behaviour leads generally to the conclusion that we don’t have much in the way of free will, and it also plays very nicely with other scientific theories we have about the world (Physics, Chemistry etc.).
Folk Psychology on the other hand, is a name for the informal theories that we all have, purely as a result of growing up in human societies. We can all explain human behaviour, because we grew up observing other people, and importantly we were passed on a framework for understanding why people do things by our parents, and other people in our society. There are no textbooks for Folk Psychology because it is not a theory that was ever formally invented. The foundation of it is what we can think of as ‘propositional’ or ‘intentional states’. These are things like beliefs and desires: ‘George wanted all the oil, and believed it to be under the plant pot, so he broke the plant pot’. When you think about it, we explain pretty much all human behaviour in this way, and we hardly even think about it. We have to remember though that in many ways this is just a theory. We don’t know anything about anyone’s internal mental states, we just assume they are there, and try and work them out based on that person’s behaviour now and in the past.
So Folk Psychology can be thought of a as a ‘personal‘ level of explanation, and neuroscientific or physicalist explanations can be thought of as ‘sub-personal‘. We can explain the same action that a person does at both levels, or with both theories. Those explanations will be different though, and might lead us to different responses.
In the context of making things for people, it’s useful to think about use cases from both perspectives. We usually want to design something to solve a problem. We can often describe the problem in terms of some current way people are thinking and behaving that can be improved.
For example say we are trying to improve an e-commerce website, and we know people often add items to their shopping cart, but don’t end up buying something. We could describe the problem in terms of Folk Psychology, saying that people either at some point stop desiring the things they added to their cart, or that there is something preventing their belief about how to complete the checkout process. Whatever we could say wouldn’t be very illuminating in this case. Or, we could take the lead from neuroscience and cognitive science and figure out that the cognitive load is too high, and affordance for important actions is too low (In English: We know from cognitive science that we only have a finite amount of attention and processing power to dedicate to tasks, and the more these stores of attention and processing power are depleted by needing to figure things out, the less we will have for later. So the more cognitive load there is (the more complicated an interface, or a problem), the less likely we will be to complete a task. ‘Affordance’ refers to the way we use design to let people know how something works, from how it looks. A button with low affordance doesn’t give someone any clues that it is a button. Not good). The point is not the details of this particular example, but rather that we can only know these things because of our sub-personal theory of how people’s minds work – we could never have found out by asking someone, or from the general, Folk Psychological way of thinking about people.
It doesn’t only work that way around though. Think about Facebook making some design decisions, perhaps deciding to provide notifications of when someone ‘likes’ one of your photos. They could conceivably come up with a complex theoretical reason for doing this, relating to the way part of our brains responds to the perception of social endorsement or something, but the theory would be ridiculously complicated to the point of being entirely unhelpful. The helpful design insight is that people want to know when other people are a) looking at their stuff, and more importantly – b) believing it is good (or ‘like-worthy’). Sure, there is probably some sub-personal description of all the events that go on when someone likes one of your photos and you see that – millions of neurons firing and neurotransmitters in two different brains activating different cognitive systems, but it is the personal theory, the Folk Psychology theory that helps us out here.
The solutions and things we create, or design, can also be thought of in terms of the new way we hope people will think and behave as a result. Just as we can look at problems at both personal, and sub-personal levels, we can also think about the solutions we are designing in these ways as well. It might very well be the case that for some specific thing you are working on, only one of the levels really yields value, but usually, you get different kinds of value from each.
The point for now is not whether one is right and the other wrong, but rather to explore the differences between the two, and use them both to understand people better.