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.40 None 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.41 Sometimes 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.44 They 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.46 In 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
Older children will copy adults’ actions even when the children know the actions are pointless.48 In one study, preschoolers watched an adult open a clear plastic box to retrieve a toy. Some of the actions were necessary, such as opening a door on the front of the box, whereas other actions were irrelevant, such as lifting a rod that lay on the top. This behaviour is unique to humans. When presented with these sorts of sequences, children copied both the relevant and irrelevant actions whereas chimpanzees copied only those actions that were necessary to solve a task. The apes behaved in a way that was directed towards the goal of retrieving the reward, whereas for children, the goal was to faithfully copy the adult. Why would children over-imitate a pointless action? For the simple reason that children are more interested in fitting in socially with the adult than learning how to solve the task in the best possible way.49
Figure 5: Hands-free adult activates switch in A, whereas adult’s arms are constrained in B (image courtesy of Gergely Csibra and György Gergely)
Developmental psychologist Cristine Legare at the University of Texas at Austin, thinks that this early blind imitation observed in children has profound implications for our species. Along with her anthropologist colleague Harvey Whitehouse from Oxford University, she has been looking at the origins of human rituals.50 Rituals are the activities that bind humans together – acts with symbolic significance that demonstrate that members of a group have shared values. All cultures have rituals for various events that are typically major transitions in life – birth, adolescence, marriage and death. These events punctuate our lives and are often associated with religious beliefs and ceremonies. The rituals themselves are typically inscrutable. There is no inherent logic to them. In that sense there are no causal laws operating, but if you don’t follow the rules then the ritual is violated. There is something about carrying them out in the correct way which gives rituals their potency. Likewise, Legare has shown that four- to six-year-olds are more likely to copy a behaviour step by step that has no obvious goal compared to one that does. In doing so, the child may be beginning to understand that there are some activities that others engage in that have no purpose but must be important precisely because they serve no obvious goal.51
Getting into someone else’s head
You cannot directly see other people’s intentions, but you have to assume that they have them. This is called mentalizing – assuming that other people are intentional because they have minds. People are not random, but rather do things on purpose because they have goals that control their behaviour. In one study,52 twelve-month-olds watched an experimenter look at one of two stuffed animal toys and exclaim, ‘Ooh, look at the kitty!’ A screen was then lowered and raised to reveal the adult holding either the kitten or the other toy. If the adult was revealed holding the other toy, the babies looked longer – they were confused by her intentions. They interpret people as doing things for a reason. If mum is looking at the sugar bowl on the table, then she is likely to pick it up but not the salt-shaker that she has not been looking at. When mum looks at and then walks over to the fridge, she does so to open it. Infants are building up an expanding repertoire of contingencies – knowing that people behave in predictable ways. When babies think that something has a mind because it appears to act as if it has purpose, they will attempt to engage in joint attention. They will even copy a robot if it appears to have a mind. By simply interacting with a baby and responding every time the baby makes a noise or an action, the robot soon becomes an intentional agent, so that babies will actively try to engage the machine and even imitate its actions.53