Bruce Hood - The Domesticated Brain - A Pelican Introduction (Pelican Books)

Young children cannot easily formulate a mental picture of what it is like to see the world from someone else’s viewpoint. The classic demonstration of this false belief perspective involves two dolls, Sally and Anne. 57In the Sally–Anne task, Sally has a marble that she puts in a toy chest before saying goodbye to Anne and leaving the house. Whilst she is out, Anne moves the marble from the toy chest and places it in the cupboard under the sink in the kitchen. The child is asked where Sally will look for her marble. Adults easily know that Sally will look in the original location. After all, she does not know that Anne moved the marble and she isn’t psychic! Again, three-year-olds fail the test and say Sally will look in the cupboard in the kitchen, under the sink.

Why does it take so long for young children to understand that others can be mistaken? After all, infants understand that adults behave purposefully when watching their actions. One explanation is that young children do not yet understand that others have minds that can harbour false beliefs. Another explanation is that these tests require individuals to make a response that runs counter to what they know to be true. They have to actively ignore the true state of the world. If the task requirements are changed so that the need to respond is taken away, then a different picture emerges. One study examining the looking behaviour of infants reveals that they will look longer when Sally, who should hold a false belief, goes to the correct location as if she knew that her marble had been moved to a new location. 58Sally’s psychic ability creates a violation of expectancy in the infants, so that they are surprised.

Appreciating that others can have false beliefs appears to be uniquely human, as there is no compelling evidence that other animals can acquire this aspect of theory of mind. As noted earlier, they can consider another’s perspective, which is how animals learn to deceive or pay attention to potential competitors; but they do not reliably pass tasks that require understanding that another holds a false belief. When tested on a similar non-verbal version of the Sally–Anne task, apes fail when required to make a choice by looking for food in one of two locations; but like human infants, they seem to register some indecision by looking longer or backwards and forwards between locations when there has been a surreptitious switch of target from one hiding place to the next. 59Together, the looking measure suggests that there is some rudimentary knowledge about mentalizing present in both apes and young infants. However, only in humans does that understanding develop into a full theory of mind that we observe in typical four-year-olds.

Working out what others know is not always as trivially easy as the Sally–Anne task. Consider more complicated plots with more characters and more changes of events. When someone says ‘I know that she knows that he knows’, then they are applying multiple theories of mind. Keeping track of who knows what can easily become more difficult with each layer of plot added. Even then, you have to pay attention because if you miss a key step or forget who did what, you get it wrong.

Add to this the trouble with knowledge. When we know something is true, it is harder to ignore the content of our own minds when attributing a false belief to others. 60We have to actively suppress our own knowledge in order to correctly identify the state of mind in another. As we shall see later, in Chapter 4, deciding not to do something requires actively doing something, which may be compromised in young children and absent in most other animals. So even adults who pass Sally–Anne tasks take longer to correctly attribute false beliefs to others. They are also much slower to solve false-belief situations when you give them a second task that occupies their own minds. It takes effort to think carefully about what others are thinking. Also, it is not clear that adults always employ a theory of mind during most social interactions. 61When you open the door for someone, do you really try to work out what his or her intentions are or do you mindlessly execute an action out of habit? Just because we can generate a theory of mind does not mean that we always do.

New York psychologist Lawrence Hirschfeld argues that while mentalizing through a theory of mind might be one way of predicting and interpreting someone’s behaviour, a better strategy, which is more accurate and efficient, is to make certain assumptions about the situation. In many of our interactions with others, we do not try to infer what is on their mind at all. Holding doors open for others, for example, is a mindless act, as are many of our social interactions. 62This is because humans may not be that good at attributing the correct mental state to others in the first place but they are better at reading what is normal behaviour in different contexts. Rather, we learn to apply a theory of society interpretation to the motivation of individuals – what people typically do in a particular situation. This would be based on learning about different members of the group as defined by the different categories they occupy, such as age and gender.

We operate with stereotypes, which lead us to assume that people will behave in certain predictable ways based on past experiences. This may actually be the default strategy for reasoning about other minds. In other words, it is when people do something we regard as unusual that triggers our mentalizing, as in, ‘What the hell were they thinking?’ This is when our false-belief reasoning is switched on, in an attempt to rationalize another’s actions. The idea that children learn about such exceptions to normality is supported by studies that show they are more likely to seek an explanation when they encounter variability in another’s behaviour. 63They are also more interested in inconsistent outcomes – like detectives trying to solve puzzling behaviour. 64They seem driven to try to understand the social world around them by making sense of people as predictable agents. Children need to learn what is typical for certain individuals as opposed to what is typical for most people.

How we make up our minds

Babies are clearly not just little adults, so what sort of creature are they? They are not blank slates: they are born with a brain that is already prepared for learning about the world. They have an instinct to learn. The development of the mind through learning must be the interaction between brain and the environment, shaped by mechanisms that have evolved to make sense of the world. But how much is built in by evolution and how much of it comes from experience?

As complicated animals, we engage in complex levels of analysis of the world. We have raw sensations streaming in through the senses that have to be organized into meaningful patterns that reflect information and structure in the environment. It would be a blooming buzzing confusion if it were not for the fact that we have some rules about how to make sense of our senses. These are the perceptual processes in the brain that detect and generate patterns. However, perceptions are only of use if they can be stored and recruited for future reference in order to plan behaviours. This is the job of cognition or thought. We can think about what we have learned and apply that knowledge to predict what to do next in a situation.

For young children, much of that world is a social one because they are so reliant on others for their survival. In the same way that we are adapted to understand some features of the physical environment, we also seem to be adapted to learning about others. Rudimentary social systems need to be fine-tuned or switched on by experience so that we can begin to understand people.

Some animals can also read other’s behaviours, but only when it is in their interest to benefit. Most animals are selfish, with little concern for others. In contrast, during the first year, a human baby’s social interactions with adults are rich and numerous but it is not clear that infants fully understand that the adult has a mind of their own yet. Without language, it is not clear that we could ever know what a baby is thinking about others. Maybe they are just like meerkats who automatically follow another’s direction of attention. However, as they grow, babies become more interactive with the world around them and seek out the attention of others. They may not have language by their first birthday but they are already communicating and reading non-verbal signals. They have gestures, squeal, blow raspberries, pull faces, protest, throw toys, point out things of interest, show fear or happiness and, of course, cry. Not only can they signal to adults what’s on their mind or at least when they are happy or unhappy, but they are beginning to understand that adults have minds too. When we can understand the minds of others, we can predict what they will do in the future. That is an enormous advantage when making sense of those around us.