A brain is a machine that has to build itself. While every newborn baby is born with a set of reflexes, it has to learn how to see, feel, and think – that is, how to be conscious – through its interactions with the world.
A baby’s brain has to learn how to make sense of its world. Consciousness – in all its sharply focused, meaning-imbued, and introspective glory – is not something that we are born with; instead, it is a brain skill that must be mastered in stages. Learning to be conscious begins in the womb. By 14 weeks, a fetus has a brain. If pricked, stress hormones surge through its body, suggesting that it feels pain.
The adrenal glands produce a stress hormone called cortisol. Because your brain releases it through the sympathetic nervous system in response to many different kinds of stress, it helps your body deal with stressful situations. The most common stress hormone is cortisol. It makes the blood have more glucose.
But such responses are just reflexes, as at this age, the higher brain is only an unconnected mass of cells. By six months, however, the brain is wired up enough for the fetus to hear, smell, taste, and even blink when bright light shines on its mother’s abdomen. Experiments show that newborns can recognize music and voices that they hear during pregnancy. So, significant learning is already taking place in the womb.
Brain growth and early experience
After birth, the brain really gets going, growing at a phenomenal rate of around a quarter of a million neurons every minute. Its rampant growth is, however, rather random. The connections established between neurons are chaotic, and nerve traffic flows spasmodically across the jumbled pathways of the immature brain. And studies suggest that a newborn’s experience of the world is very different from our own. In one experiment, babies were shown a number of simple patterns; electrical recordings revealed that their brains took in the information very slowly and responded with much the same surge of neural firing to one pattern as to another. So newborns can certainly see, but what they experience – with the likely exception of the mother’s face and breast – is Little more than an elusive, shifting shape.
But soon, the baby begins to acquire the habits of perception – interpreting information from the senses in a way that nukes the sense of the world and provides the basis for conscious experience. To carry out this wiring, brain growth actually goes into reverse. Links between neurons are severed, and some cells die, pruning- back the forest of connections into a more efficient network. The brain discovers through experimentation the connections that can deliver focused impressions, and a result is a thinking machine that is shaped to fit its world.
Models of development
There have been many attempts to unravel the thinking processes by which children learn and adapt to the world. The two best-known pioneers in this area are Jean Piaget and Lev Vygotsky.
The Swiss psychologist Jean Piaget (1896- 1980) was a sharp observer of children, and he noticed that their cognitive development red to follow a natural succession of stags. Just as most children learn to crawl before learning to walk, intellectual development takes place in more or less distinct steps. Piaget stressed the role of the individual child in bringing about his or her intellectual development. Like miniature scientists, children are always experimenting – banging objects, playing around with them – and gradually developing rules that allow them to understand their world.
The child begins by establishing some very general expectations about the world. At about eight months, for example, a child will have learned enough to know that when a blanket hides a toy, the toy still lies underneath it. Later, the child has more sophisticated expectations, learning, for example, that matter is conserved. So when a tall, thin glass of water is poured into a short, fat glass, the child knows that the quantity of water is the same in each, despite the different levels of water in the glasses.
The development of a sense of self characterizes another important stage. While most children can recognize themselves in a mirror by the time they are two years old, Piaget considered them to be ‘egocentric’ until the age of five or six. At this age, children begin to realize that other people may see and feel life from quite a different point of view; they also learn that inner psychological events, such as thoughts and imaginings, are distinct from real events in the outside world. The new ability to put themselves in another’s shoes, in turn, strengthens children’s perception of self11ood – they can be objective about their subjective existence and have more mature emotional reactions and moral judgments.
Piaget’s model of development was incredibly ambitious because it described the complete transition from birth to adult thinking. Many psychologists have challenged the way Piaget reached his conclusions and have pointed out that he did not try to account for how or why development occurs; nevertheless, Piaget’s ideas remain one of the most prominent influences in developmental psychology.
Social theory
The theories of Russian psychologist Lev Vygotsky (1896- 193 4) place far more stress on the role played by society and language in shaping the minds of children. Vygotsky pointed out that not only are all children born into the same physical world – and so will learn the same sensory and perceptual lessons – but they are also born into well-defined cultural worlds. So, their interactions with other people will be a crucial factor in their mental development. Vygotsky showed how children learn to express their thoughts in words, first through talking out loud, then by internalizing the tr speech as a private monologue – a habit of wrestling ideas from the self. Vygotsky argued that many of the things that we consider to be part of our conscious selves are actually the internalization of socially evolved ways of thinking. Such attitudes like loyalty or rebellion, rather than coming from within, are, in fact, learned from ideas expressed within our cultures.
Lifelong development
Both Piaget and Vygotsky’s theories conform to the common sense idea that babies are born and then develop increasingly complex minds, each new set of mental skills paving the way for further levels of elaboration. But what has recently astonished psychologists is that the human brain seems genetically programmed to develop over a prolonged period. Until relatively recently, psychologists assumed that the brain completed its growth and subsequent pruning in the first few years of life, ending with the language centers, which reach maturity at around six or seven. Yet brain scans have shown that the very highest level of the brain – those that have most to do with planning, social judgment, and emotional control – have a sudden surge of growth just before puberty and then are gradually shaped during the teen ao-e years and even early adulthood.
Drug use during the critical period of mind development, particularly in adolescence and young adulthood, can have profound and long-lasting effects on the developing brain. The brain undergoes significant changes during this period, with key regions responsible for decision-making, impulse control, and emotional regulation still maturing. Drugs can disrupt these processes, leading to a range of cognitive, emotional, and behavioral consequences. Substance abuse can impair memory, attention, and learning abilities, hindering academic performance and overall cognitive functioning. It can also alter the brain’s reward system, leading to a heightened risk for addiction and substance dependence later in life. Additionally, drugs can impact emotional well-being, increasing the likelihood of developing mental health disorders such as anxiety, depression, and psychosis.
What this appears to mean is that evolution expects us still to be learning important intellectual lessons at this relatively advanced age. The necessary plasticity has been designed so that we can assimilate a socialized mindset in a gradual, step-by-step fashion. If the behavior of an adolescent seems immature (or interestingly experimental, as a teenager would see it), this is because it quite literally is so. The human mind was meant to develop through a prolonged process of adjustment before finally arriving at a state of well-adjusted fit with its environment.
Newborn Brains
The idea that human babies are born with largely unwired brains appears to be contracted by two observations. First, experiments show that babies can recognize their mother’s face on the day they are born. Second, babies only a few hours old can mimic facial expressions. If you pull a happy, sad, or surprised face, a baby can produce a rough copy. These feats should be impossible because a baby’s cortex has hardly any connections at this stage. The explanation seems to be that newborns are using the midbrain and the amygdala, structures in the more primitive core of the brain that matures in the womb. This early ability to recognize and copy expressions takes place at a reflexive, unthinking level and only takes on meaning when the cortex develops. This also explains why children develop ‘stranger anxiety at around six months, once they begin to see the world at a more conscious level.
Teenage Development
Some researchers believe that adolescence Is a life stage unique to humans – unlike most other primate species, which generally go straight from childhood into adulthood. Anthropologist Barry Bogin believes that his pattern of development evolved to allow young humans time to master the intricacies of adult social relations.
According to Bogin, the fact that boys’ and girls’ physical development follow some Nhat different courses bears this out. Boys Become fertile and hormone-driven at about 13, yet their bodies stay puny and sexually unappealing to females until muscle development in their late teens. Girls grow a womanly shape at puberty yet are surprisingly infertile until their late teens.
The theory is that girls needed to look like women before they reached sexual maturity so that they would be included in the routine of baby care, allowing them to pick up the essential skills of mothering. Boys needed the sexual drive and aggression of an adult male while still resembling unthreatening children so that they could learn their roles in society without provoking jealousy and violence from elders.
