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

Mind games

By signalling the focus of another’s interest, gaze monitoring enables humans to engage in joint attention. How many times have you been in the company of a bore at a party who is droning on and you want to leave with your partner or friend but cannot tell them directly? A roll of the eyes, raised eyebrows and a nod of the head towards the door are all effective non-verbal cues. Even if the other person is a stranger or does not speak your language, you would be able to understand each other without exchanging a word. Joint attention is the capacity to direct another’s interest towards something notable. It is a reciprocal behaviour; you pay attention to what I am focused on and, in return, I pay attention to you. When two individuals are engaged in joint attention, they are monitoring each other in a cooperative act to attend to things of interest in the world.

Other animals, such as meerkats, can direct attention by turning their heads to signal a potential threat. Gorillas interpret direct gaze as a threat, which is why there is a sign at my local Bristol zoo where Jock the 34 stone 6 foot silverback male lives telling visitors not to stare at him. Jock pays attention to gaze as a source of threat, but we are the only species that has the capacity to read the meaning of the eyes over and beyond sex and violence (domesticated dogs being the notable exception that we described in the opening to the book). We use other people’s gaze to interpret the nature of relationships. People who know each other exchange glances and those in love stare at each other. 36This explains those awkward moments that we have all had when we exchange a glance or stare with a stranger in the street or, worse, in an elevator where it is difficult to walk away. Do I know you? Or do you want to be friendly or fight? At a party we can look around and work out who likes each other just by monitoring patterns of joint attention. This ability to work out ‘who likes who’ based on gaze alone develops as we become more socially adept. Six-year-olds can identify who are friends based on synchronized mutual gaze, but younger children find it difficult. 37Joint attention in younger children and babies is really just from the child’s own perspective. If it does not involve them, then they are not bothered. As children become socially more skilled at interacting with others, they start to read others for information that is useful for becoming part of the group.

Joint attention may have evolved as a means to signal important events out in the world in the same way that meerkats use it, but we have developed gaze monitoring into a uniquely human capacity to share interests that enable us to cooperate and work together. No other animal spends as much time engaged in mutual staring and joint attention as humans.

Gaze monitoring is also one of the basic building blocks for social cooperation. We are much more likely to conform to rules and norms if we believe that we are being watched by others. A poster with a pair of eyes reminiscent of George Orwell’s ‘Big Brother’ makes people tidy up after themselves, follow garbage separation rules, voluntarily pay for beverages and give half as much again to charity boxes left in supermarkets. 38Even though individuals may be totally alone, just the thought that they might be watched is enough to get most people to act on their best behaviour. Other people’s gaze makes us become more self-conscious, prosocial and likely to conform.

It is notable that humans are the only primate out of the 200-plus species who have a sclera enlarged enough to make gaze monitoring so easy for us. In humans, the sclera is three times larger than that of any other non-human primate. If you think about it, evolution of the human sclera could not have been for the benefit of the individual alone. There would have been no selective advantage for me with my big white sclera unless there was someone else around to read my eyes. Rather, it had to be of mutual benefit to those who can read my eyes as well as myself. 39It is only of use within a group that learns to watch each other for information.

When infants are learning words from an adult for things they have never encountered before, they listen out for the new name but also monitor where the adult is looking. In one study they were shown a new object and when they were looking at it the experimenter said ‘Look at the toopa’ but at the same time was herself looking into a bucket. 40None of the children associated the word ‘toopa’ with the object they were holding. Children understand new words refer to new things but only those that are introduced in the context of shared joint attention.

By their first birthday, babies are constantly monitoring the faces of others, looking for information, and have even mastered the skill of pointing that can alert another to something of interest. Initially, babies point because they want something out of reach. Many primates raised in captivity do this as well, though it is more of an open-handed gesture to receive food. Apes also lack the hand anatomy that allows them to extend the index finger in the same way that humans do. However, only human infants will point to things out of sheer interest. 41Sometimes this is done to solicit a response from an adult, but more often than not the youngster is simply pointing out something interesting to be shared. No other animal does this. 42

Copycats

In addition to joint signalling, we also copy each other. Initially, parents and babies enjoy copying each other’s expressions and noises in reciprocal exchanges. Adults instinctively speak to young babies in that high-pitched, musical, gibberish language in an attempt to elicit smiles and laughter. 43(You may have noticed that couples and pet owners can also do this.) Adults attempt to match the behaviour of the infants because babies respond to it. Sometimes, babies take the initiative and begin to spontaneously copy others around them.

These imitative behaviours are not just limited to language. Facial expressions, hand gestures, laughter and complicated actions can all be observed. Imitation signals to others that we are like them too, and we are the best imitating species on the planet. Andrew Meltzoff from the University of Washington thinks that babies really do this to establish a ‘just like me’ relationship with the adult. 44They are using imitation to identify others as friend or foe. The mechanism works both ways. When adults mimic the facial expressions of infants back to them, these signals are telling the baby that this person is one of them. 45

Before the child has reached their second birthday, they will copy all manner of behaviours. However, this is not slavish mimicry triggered automatically but rather an attempt by the infant to get into the mind of the adult. After watching an adult ‘fail’ to pull the end off a toy dumbbell, eighteen-month-old infants will read the true intention of the adult and complete the task they had never seen before. 46In one study, shown in Figure 5, fourteen-month-olds watched an adult experimenter bend over and activate a light by pressing the button with her head (A). For some of the infants, the adult’s hands were bound by a blanket (B).

The babies were then given the light switch to play with. Infants who saw the adult whose arms were bound (B) activated the light switch with their hand because they understood that the adult was unable to use their hands. However, if they were the ones who saw that the adult’s hands were free (A), then the infants bent over and activated the button with their head too. They must have reasoned that it was important to use the head and not the hands. Infants were not simply copying the actions but rather repeating the intended goal. They had to get into the mind of the experimenter in order to work out what they wanted to achieve. 47