Theory of Mind

The theory of mind is a universal human ability that we didn’t even realize existed until we began studying autism. In this context, “theory of mind” is simply a term that refers to our human capacity to understand other people—not just in terms of their behavior, but in terms of their thoughts and feelings. Everything that happens in our heads is, of course, invisible, but we build a theory about what our own mind is doing. That’s why it’s so important to mention autism when we talk about theory of mind. This isn’t a theory in the philosophical sense, nor is it an explicit theory—it’s an intuition.

We act as if we know that the beliefs, desires, and feelings that make up our personality allow us to predict what we’ll do next. For example, if John leaves the house with an umbrella, it’s not necessarily because it’s raining right now: maybe it’s not raining, but John believes it will. This isn’t about the actual state of reality—it’s about beliefs. We believe that people with autism lack this ability, which leads to their difficulty with two-way interactions: they can’t track, moment by moment, what another person might be feeling, knowing, or thinking. It’s as if our brains have an invisible GPS navigator that helps us move through the social world, even though we’re not consciously aware of it. People with autism, on the other hand, have to use a much more cumbersome map, which takes more time. Think about it: everyone likes having a GPS in their car because it does part of the work for us and gets us to our destination without us having to think about it.

The term “mentalization” was coined for theory of mind, though it’s not a very appealing word. We can mentalize, and by doing so, predict what people will do and explain why. Of course, mentalization also gives people the ability to lie—the capacity to understand whether someone knows something and whether it’s possible to plant a false belief in their mind, and then track it. This is a very important tool for our social interactions, though it’s not always used for good. People with autism are often said not to lie and not to understand why typical people lie so often, even when it’s unnecessary—like to make someone feel good or to flatter them. All our rules of politeness are tied to this subconscious mentalization program that tells us, “We don’t want to hurt the other person’s feelings.” We’re constantly checking the other person’s reaction to see if we’re doing things right and if we’re understanding them correctly.

This is a pretty abstract idea, so many people say, “That’s just silly! How can you claim that mentalization is a special ability, like hearing or color vision?” I actually think it is: the ability to recognize invisible mental states in others is similar to color vision, which means it has a basis in the brain. This has been proven using neuroimaging methods: we asked people to perform tasks that required recognizing another person’s mental state, and then compared them to similar tasks where this wasn’t needed. One example is tracking the movement of objects: people’s intentions and beliefs can be expressed through movement, and you consciously interpret them not just as simple physical cause and effect. We can study people’s reactions to watching videos or reading stories—various methods are used to analyze what’s happening in the brain, and we see activation of a specific network of brain regions. It’s a real network, including frontal and temporal areas, which are well-connected in typical cases and less so in autism. So, theory of mind has a biological basis.

The Evolution and Development of Theory of Mind

Mentalization and theory of mind have changed our understanding of the development and evolution of the human mind. One of the first questions that comes up when discussing theory of mind is: where did this ability come from, evolutionarily? Is it unique to humans? Future research will focus on this area, and there are already studies on very intelligent birds from the corvid family: they hide food, and if they know another bird is watching, they’ll come back and move it to a new spot. That’s theory of mind at work. It’s logical to assume that this also works in other species—it will be very interesting to see if that’s the case.

However, this theory of mind doesn’t involve language. We assume that humans may have two theories of mind: an automatic one, and another that’s tied to language and can be used to analyze our own minds. This is another area that needs further research. We need to figure out why people can consciously reflect on what they think, want, and feel. So, there’s still a lot of work to be done in this field. It’s important to understand whether there’s a hidden, automatic form of theory of mind, whether other animals have it, and whether there’s also an explicit, conscious form of theory of mind—or maybe there are other forms we haven’t discovered yet. Is the explicit form of theory of mind that a typical child develops based on the hidden form, or is it a completely independent ability? These are all open questions today.

Theory of Mind vs. Empathy

Some people confuse empathy with theory of mind or mentalization: it all sounds like it’s related. However, by studying autism with neuroimaging, we’ve found that these are different concepts. While mentalizing means taking emotions into account or tracking their changes, empathy is a different ability, based on another system in the brain, which works a bit like an infection. I feel what you feel, and if you laugh, I’ll probably laugh a little too. Maybe I won’t show it, but with small devices attached to people’s faces, we’ve found that the muscles involved in laughter activate when someone else laughs, and you’re ready to laugh yourself. This is an automatic mechanism, a primary form of empathy, so we really do feel other people’s pain and joy. Interestingly, in autism, this ability usually remains intact, so not all social skills are absent in this condition—only mentalization is missing.