by Bruce Hood
Baby Bat Brains
Now that you know the basic architecture of the developing brain is one designed to learn from others, I expect you are wondering what it must be like to think like a baby. To answer that, let’s consider this problem from the perspective of what it must be like to be an animal.
The philosopher Thomas Nagel42 famously asked, ‘What is it like to be a bat?’ Most of us with vivid imaginations can contemplate being much smaller, having fur and even wings (who has not dreamed of being able to fly?), but we cannot really know what it is like to be a bat. A bat would not have the mind of a human, because its brain is different and so you cannot use your human mind to experience being a bat. As a bat, you would not be able to see in the way that humans do because your vision is so poor. You would have to rely on echolocation, which is why bats squeak when they fly as a way of mapping out the air space in front of them and identifying tasty insects to eat. A bat probably has more in common with a dolphin than a bird. The list of differences goes on, but the point is that you can never know what it would be like to be a bat for the simple reason that you have a human brain and a mind. The same applies to human babies.
The developmental psychologist John Flavell once said that he would trade all his degrees and honours to spend five minutes in the mind an infant – just to experience what it must be like to be a baby again.43 That would probably be a waste of his academic accolades. Just think about it for a moment. How could you see inside the mind of another person let alone a baby? Human babies have human minds but those minds are very different to one that we could appreciate as adults. If you had an adult mind inside the body of a baby, it would not be the same as thinking and experiencing the world as an infant. You would have to abandon all the knowledge and reasoning that you have built up as an adult. You would have to think like a baby. So you would not have an adult’s mind thinking like a baby. You would be a baby. As much as we might try, we can never get a true sense of what it is to have the mind of an infant. Every parent falls for this trick. When we stare at our infants in their cribs, we try to second-guess what they are thinking. We try to imagine what it must be like to be them, but for all our wishful thinking, they might as well be a bat.
An infant’s mind may be very alien to us but it is one that will eventually become an adult mind. Nature has built into humans the capacity to learn and to learn very quickly from others. It is not only doting adults who focus their attention on their offspring; each baby is wired to pay attention to others. It’s how our species has evolved a remarkable ability to transfer knowledge from one generation to the next and no other animal on the planet can do this as well as humans. But do babies know who they are? Babies have conscious awareness but does a baby have a sense of self yet? We cannot know for certain but I suspect not. Beginning the process of creating the self illusion requires early social interactions.
2
The Machiavellian Baby
The development of the child’s personality could not go on at all without the constant modification of his sense of himself by suggestions from others. So he himself, at every stage, is really in part someone else, even in his own thought.
James Mark Baldwin (1902)1
Hitler was one – so was Mother Teresa. Every monster or messiah has been one. We were all babies once. We have all been cherub-like angels, blameless and innocent of any crimes and, in most cases, the apple of someone’s eye. But somewhere along the way, some of us lost our innocence. Some of us became evil. Some of us became good. Some of us became bankers. However we turned out, we all discovered our sense of our self along the way. How did that discovery happen?
People used to think that the infant’s mind was completely empty at birth, and then filled up with information from the world around. The eighteenth-century English philosopher, John Locke, described the mind of a newborn infant as a blank piece of paper upon which experience would write itself.2 William James, the nineteenth-century American philosopher, thought the newborn’s world was a chaotic jumble of confusion.3 Both were wrong in assuming that a baby has no built-in abilities and that all experience is total chaos. Natural selection has been busy creating human brains ready for certain information. Like your laptop computer delivered through the mail, babies come with a brain operating system that has evolved to learn certain things about the world and ignore other stuff that is not of use to them. And the most important things to a human baby are other humans. Human infants are wholly dependent on others and, as mentioned, spend the longest proportion of their lives in this state of dependency compared to any other species. Why?
Approximately 250,000 years ago, a few thousand Homo sapiens migrated out of Africa aided by a brain that was sophisticated enough to adapt to new environments, but also one that had evolved the capacity for the transmission of knowledge from one generation to the next. We were born to learn. Long before writing and the Internet were invented, humans had the capacity to communicate with each other in ways that no other animal could. With communication came an explosion in technology and skills. This was not information in our genes but rather knowledge gleaned from others. Our parents, and their parents and their parent’s parents before them, had thousands of years of knowledge passed down from each generation. That’s why every newborn baby does not have to start from scratch. This is such an obvious fact about human civilization that we often forget that we are the only animals on this planet that retain skills and knowledge that we pass on to our offspring. Other animals can learn about their environments but no other animal has the human capacity for acquiring thousands of years of experience within a lifetime.
The best way to tap into that knowledge is to pay attention to others, which is why humans spend so much time as children. Other species that spend comparatively longer periods as juveniles also end up smarter than their cousins who reach adult maturity more quickly. For example, crows are a remarkably clever family of birds that are capable of solving many more complex problems that behavioural bird experts throw at them compared to other birds, such as chickens. After hatching, chickens are up and pecking for their own food much faster than crows, which rely on the parent bird to bring them food in the nest. However, as adults, chickens have very limited scavenging skills whereas crows are much more flexible in foraging for food. Crows also end up with bigger and more complex brains, which is why they are sometimes referred to as the ‘feathered apes’ because they are as clever as chimpanzees. Their extended fledging period enables them to develop intelligence. Across various animals, childhood has been compared to the research and development phase of the life cycle.4 Those species that spend longer in R&D end up with a larger repertoire of skills and not surprisingly, also end up the most sociable.
In humans, not only do we learn from others about the world around us, we also learn to become a self. In the process of watching others and trying to understand them, we come to discover who we are. During these formative years, the illusion of the reflected self we experience is constructed by those around us through our social interactions.
On the Face of It
Brains got bigger as a way of coping with the processing demands of increasing group size. You need big brains to think about people so that you can negotiate the best path through the social landscape. You have to be cunning and that requires the ability to anticipate what others are thinking. In order to be a successful Machiavellian primate,5 as another famous Italian, Don Corleone, would say, ‘You need to keep your friends close but your enemies closer still.’ In other words, you have to be vigilant for those who wish to take advantage of you.
One of the first things you need to do is identify important individuals in the group. You have to be choosey. It’s no good trying to apply the same interactions to everyone. Imagine the problems you would create if you were a sexually active male, and could not distinguish between your mother, sister and your girlfriend when it came to sexual advances. It is important from an evolutionary point of view (not to mention
social cohesion) to distinguish between individuals and one of the most important ways humans identify others is to rely on the uniqueness of faces.
Faces are an unusual class of patterns because they all share the same basic structure of two eyes, a nose and a mouth. Yet despite the similarity, the average human can recognize thousands of separate faces. This facial expertise is supported by neuronal circuitry in a region known as the fusiform gyrus, a cortical region located just behind your ears.6 It is active when we look at faces, and if you are unfortunate enough to have this area damaged (especially on the left side), then you may suffer from a condition known as prosopagnosia, a kind of face-blindness. Prosopagnosics can no longer tell faces apart and fail to recognize those that were once very familiar.
Our love of faces begins very early. Like Lorenz’s goslings that followed the first moving thing they saw, human newborns have built-in brain circuitry for following faces.7 Even though their vision is bad enough to qualify them as legally blind, faces are like magnets to young babies. They can hardly take their eyes off a human face even if it is just a rudimentary pattern made up of two dots for eyes and a third for a mouth. This initial preference for face-like patterns is quickly replaced by a system that learns to recognize specific faces. By six months, if you show infants a face they have never seen before, they easily remember it much later. They are learning who’s who. But it’s not just human faces. Six-month-old infants recognize both human and monkey faces. However, by nine months, babies lose the ability to tell the difference between monkey faces much as we do as adults.8 It’s another example of a sensitive period with brain plasticity that becomes increasingly tuned in to experience. What is remarkable (but not if we remember that we, too, are primates) is that baby monkeys also seek out any face, either monkey or human, but become more tuned into those to which they are exposed. We know this from studies of monkeys raised without seeing faces in laboratories where the human handlers wore blank masks to cover their faces.9 If monkeys never see faces, they lose the ability to tell any faces apart. If they see only human faces, they get good at telling humans apart. This selective responding to faces is another example of the ‘use it or lose it’ principle, in which the neural networks are tuning into early experiences to create a permanent record.
Early face experience also shapes human brains. For example, children born with cataracts never see faces clearly as infants. When their vision is surgically corrected later in life, they still have problems with recognizing faces even though they can then see clearly.10 No matter how much training and practice you have later in life, some early exposures are important for shaping brain development. So when Tarzan returned from the jungle to take up his position as Lord Greystoke, he would have had a problem telling the difference between the cook and the scullery maid, having never seen a human face as an infant. His recognition for ape faces at the zoo, on the other hand, would have been just fine.
The same goes for telling the difference between individuals from another race. Unlike most adults who think members of other ethnic groups look very similar, babies initially have no problem. They can tell everyone apart. It is only after exposure to lots of faces from the same race that our discrimination kicks in. However, you can train babies not to become tuned into their own race if you keep exposing them to faces from other races.11 So the next time you think that other races all look alike, don’t worry, it isn’t racism – it’s your lack of brain plasticity.
Smile and the World Smiles with You
Brain development requires more than just mere exposure. Having found a face as a newborn, what do you then do? As human infants are born so immature, they cannot waddle towards our mothers like birds can for at least another ten months or so. Yet it would appear that young babies are naturally inclined to get a rise out of adults by copying them – or at least responding in a way that adults think is an attempt to imitate. That’s right, if you stick your tongue out at a newborn baby, sometimes they will stick their tongue out right back at you.12 Even baby monkeys do this.13 It’s not the same as bratty children in the rear window of a bus giving you the finger or pulling facial grimaces, but if you wait patiently, a newborn may try to copy your expression. The reason that this is so remarkable is that it means humans enter the world ready for social interaction.
After tongues, comes the smiling. By two months, most infants will readily and spontaneously smile at adults. This is a magical moment for any parent. Brain imaging studies reveal when mothers look at pictures of their own smiling baby in comparison to those of other babies, the circuits in the reward centres deep in their brain known as the nucleus accumbens light up.14 These are the same circuits that get turned on by flowers, chocolate, orgasms and winning the lottery. No wonder social smiling is considered intensely pleasurable.
I vividly remember my own utter surprise and joy when my eldest daughter smiled at me for the first time. It wasn’t so much a smile but a burst of laughter and giggling (she has been laughing at me ever since). Even as an expert on infant behaviour who knew that social smiling can be expected around this time, nothing could prepare me emotionally for my daughter’s first smile which thrilled me and sent me hurrying off to tell anyone who would listen. In some cultures, such as the Navajo of North America, this first social smile of a newborn is a time of celebration and the person who sees this is considered enriched and should hand out gifts to all members of the family. They say the individual has arrived in the tribe.15
With a simple pull of twelve facial muscles, our Machiavellian baby can control the adults around them with a smile. When babies smile at us, we smile back and it feels great!16 This is because smiling triggers the corresponding happy feelings in the emotional centres of our brain that are usually associated with this facial expression. Even forcing a smile by getting someone to bite down on a sideways pencil makes them happier than if they are asked to suck the pencil, which makes them pout.17 Copying each other’s expressions makes us feel differently, which is one reason why emotions can become almost contagious between people. In fact, we tend to only smile when there are others around. In one study, players in a tenpin bowling alley were found to smile only 4% of the time after a good score if they were facing away from their friends but this increased to 42% when they turned round to face them, indicating that this expression is primarily a signal to others18.
Smiling is linked to the development of the brain regions that support social behaviour, which are located towards the front of the brain in a cortical area known as the orbital cortex because it sits over the orbits of the eye sockets. Although smiling has been observed using ultrasound in unborn babies, indicating that it is a hard-wired behaviour, at around two months it operates in combination with the higher order centres of the brain that are recruited for social interaction.19 At two months, the baby is already using a smile to control others.
The built-in capacity for smiling is proven by the remarkable observation that babies who are congenitally both deaf and blind, who have never seen a human face, also start to smile around two months. However, smiling in blind babies eventually disappears if nothing is done to reinforce it. Without the right feedback smiling dies out, just like the following instinct does in goslings. But here’s a fascinating fact: blind babies will continue to smile if they are cuddled, bounced, nudged and tickled by the adult20 – anything to let them know that they are not alone and that someone cares about them. This social feedback encourages the baby to continue smiling. In this way, early experience operates with our biology to establish social behaviours. In fact, you don’t need the unfortunate cases of blind babies to make the point. Babies with sight smile more at you when you look at them or, better still, smile back at them. If you hold a neutral or worse, a still, impassive face, they stop smiling and get quite distressed. By the time the baby is six months old, they will cry at angry faces and frown at those that look sad. Babies expect and prefer adults to smile at them. Who doesn’t? It’s a universal expression first rec
ognized by Charles Darwin as one of the core components of human social interaction.21
Laughing Rats
Laughing and smiling are not just signals for others that we are like them, they are strong emotional drives that bind us together as a social species. They are just some of the mechanisms that begin to integrate the individual into a group. When my infant daughter burst into laughter, she was demonstrating one of the most powerful primitive needs to make contact. Without the ability to laugh and smile, we would be isolated individuals. We use laughter to lubricate awkward social interactions, as a way of signalling that we are easy-going, not aggressive and potentially someone worth investing time and effort in. In short, we use laughter to generate our reflected self because our sense of self depends on what others think of us and being funny is considered by many in our culture as an important measure of who we are. It is one of the reasons that most of us think we have a better than average sense of humour – although statistically, that cannot be true. Very few people would readily admit that they do not have a sense of humour. It’s one of the main attractive features that singles use to describe their attributes in personal ads. People who take themselves too seriously are regarded as cold and distant, whereas those who make us laugh are more likely to be considered warm and approachable.
Without the ability to laugh, it is difficult to imagine how we could ever endure life’s challenges. Even during the worst imaginable atrocities of the Nazi concentration camps, there was laughter. Viktor Frankl, a psychiatrist who survived the Holocaust, wrote how laughter was the one thing that helped many survive.22 In his memoir, Terry Anderson, who was held hostage in Lebanon for 2,455 days during the 1980s wrote about how his fellow prisoners coped by using humour.23 One captive told shaggy-dog stories. Another mimicked the guards. The laughter made the unbearable situation bearable. Maybe this is why in the wake of every shocking world event where lives are lost, someone comes up with the inevitable ‘sick’ joke. It’s as if we need laughter as a release mechanism for pent-up anxiety. Freud coined the term ‘gallows humour’ and described how it operated as a defence mechanism when confronted with the prospect of death. In such times, laughter can afflict us like a sneeze that cannot be suppressed. I know this because as a teenager at my own father’s funeral, I was overcome with a fit of giggles that I could not stop – something that I felt guilty about for years until I realized that this was a common reaction to stress.