The Social Brain And Babyhood

What shapes us into the people we grow up to become? This question has had scientists and researchers drawing conclusions over nature, nurture, or both debates for more than a century. Is it one’s genes, or environment, that define who we grow up to be?

Why Love Matters (2004) by Sue Gerhardt looks deep into the latest research in neuroscience, psychoanalysis, and biochemistry to give an insight into the early years of an individual are intrinsic to shaping the humans they become in later life.

Her research brought up a new thought – that it is during the first two years of life that genetics and social environment work together to inscribe our personalities into the brain. How an individual is treated as an infant, creates permanent neurological patterns that stay with people for life. 

Furthermore, it discusses the implications this new information has for parents.

How The Brain Evolved

Humans are social animals. As opposed to a tiger that remains a tiger whether it wanders alone in the forest, or is kept with other tigers in a zoo, social relations define humans. Essentially, it is the social brain that differentiates humans from animals.

According to neuroscientists, humans have triune brains – that is three brains in one – that reflect a different stage of evolution.

In the first stage of evolution, the brain development was similar to those of reptiles, which had a simple cognitive setup based on the brain stem allowing basic life functions like breathing. In the second stage, the brain evolved into a mammalian brain that developed around the reptilian brain, making way for basic emotions that helped in nurture. In the third stage, the human brain evolved further, where the cerebral cortex developed around the outer layers of the mammalian brain, making it a social brain, and giving humans their ‘human’ qualities.

This social evolution of the brain allows humans to go beyond instinctive ways of behaving and gets activated when humans experience empathy, follow social cues, and control their emotions.

This evolution enables humans to experience more than just primary emotions such as satisfaction, anger, and fear; intermediary emotions that are a diversification of the basic emotions, such as sadness, guilt, love, shame, pleasure, etc. can be experienced too.

In a newborn baby, the brain relies on several systems to ensure survival. The functional nervous system helps it breathe, the visual system tracks movement, and a core consciousness in the brainstem enables it to react to sensory stimuli such as temperature. However, its social brain is not developed yet.

Why Love Matters (2004) by Sue Gerhardt
Why Love Matters (2004) by Sue Gerhardt

Quality Of Social Interaction

Babies don’t have the brain capacity to control their behavior, as their social brains are not developed. Thus, when parents try to ‘discipline’ a baby that is refusing to eat vegetables for over an hour, they can’t understand the parent’s frustration. It does not understand that eating the veggies will make the mother happy.

The development of the social brain is a complex process. The orbitofrontal cortex, a key part of the social brain responsible for ‘emotional intelligence’ needs to develop. According to neuroscientist Daniel Goleman, without this part of the brain, social life gets impaired. People with injuries to the orbitofrontal cortex find it difficult to understand social and emotional cues, and could even be sociopathic.

The orbitofrontal cortex develops and gets molded by one’s experiences in the formative years of childhood. The development of the brain that takes place due to experiences is called ‘experience dependency’, which can be attributed to evolution. Essentially, humans can learn to ‘fit into’ the culture they are born within and pick up the norms and rules of the culture. However, the brain’s plasticity, or its ability to be molded, makes it vulnerable to damage too.

Harry Harlow the primate researcher conducted an experiment in the 1930s. He found that when a monkey is isolated for the first year of its life, it effectively becomes autistic. Thus sociability is dependent on social interaction.

In recent research conducted in Romania, researchers who studied brain scans of orphaned three-year-old children born in the orphanage found that they had large empty spaces where the orbitofrontal cortices should have been found. Having little adult contact, these children had been neglected, proving that social deprivation in infancy led to permanent brain damage.

Senses That Make Social Interaction Pleasurable For Babies

A baby, before it learns about human culture, has to be invited into it. This invitation to participate depends on the interlinking of the biochemical in its brain and the behavior of caregivers. Together, these make social interaction pleasurable for a baby.

Pleasurable social interactions help foster an infant’s cognitive development that in turn, strongholds the base for emotional control in adult life, as pleasure stimulates the orbitofrontal cortex. Hence, as long as parents take pleasure in the relationship with their babies, there is nothing to be concerned about.

An infant first finds pleasure in the sense of touch. For example, when a father lovingly cradles his baby in his arms, the sense of warmth and safety has an immediate physiological effect. Firstly, the baby relaxes and its breathing slows down. Next, the baby’s nervous system and heart rate synchronize with the father’s. 

These slow but sure physiological experiences are the foundations of human culture. They are the reason why, while comforting a bereaved person, we hug. They are also the reasons why a good massage helps relieve stress and tensions better than most other things.

Looking, or visual sense is the next source of pleasure. A mother’s pupils dilate when she sees her baby up close. Thus, as the baby looks into its mother’s eyes, it ‘reads’ this dilation as pleasure, which triggers a biochemical chain reaction that is triggered by its aroused nervous system. As the infant’s heart rate increases, neurons release beta-endorphins – opioid-like molecules – into the orbitofrontal cortex region. These trigger a sense of pleasure, which regulates levels of glucose and insulin, stimulating neuron growth in turn.

Simultaneously, dopamine is released in the prefrontal cortex by the brainstem, enhancing the uptake of glucose and promoting the growth of prefrontal brain tissue.

This is a microscopic description of what happens when a baby feels pleasure. However, if we look at it from a social interaction standpoint, we can see that looking at a parent’s eyes is pleasurable for a baby, and the more it looks at its parents, the more its social brain grows.

Social Patterns Determine The Brain’s Neural Network

Our genes are essentially a blueprint or a sketch, rather than the actuals of structure. However, the process of building the structure also takes into consideration social inputs from the brain to determine how much of the genetic sketch is realized in the new individual.

Humans are born with all the neurons they will ever have in their lifespans, and genes determine this. But as the baby grows, and its brain grows twice in size in the first year itself, these neurons require to be connected. Essentially, genetics and the baby’s social interaction factors combine to work out the shape of its brain.

Between six to twelve months of a baby’s birth, cognitive construction is at its peak. By the end of this peak period, a dense network of cognitive possibilities emerges. Though still incomplete, it is the foundation that eventually becomes the mind.

In the next phase, the brain begins ‘pruning’, or gets rid of those connections that are rarely used. Obsolete brain cells die, shrinking the vast network. According to the American neuroscientist Daniel Siegel, the brain works as an anticipating machine that helps in navigating the world around us by providing expectations of possible outcomes. Thus, a baby unconsciously starts noticing patterns as its brain starts categorizing experiences. The brain thus keeps the information that doesn’t help it navigate.

For example, a baby registers that diaper changing is an unpleasant activity, as it registers that its mother wrinkles up her nose in disgust, every time she changes its diapers. The repetition leads to expectation.

The Human Stress Response

Stress, in any form, can be overwhelming and draining. While in conversation, it is often associated with having a tough day, or mostly being an integral part of adult life, it, in fact, is present throughout.

Response to stress can be dated back to prehistoric ancestors and is an evolutionary reflex. When our ancestors faced life-threatening dangers, the brain released cortisol. Cortisol worked like a red signal to the other organs, to redirect all resources to deal with the emergency.

While modern society is much safer, survival today encompasses social acceptance and status, which when threatened, leading to the release of cortisol, triggering the old stress response.

Cortisol, in the short term, can be useful to help break down protein and fat, converting them into energy. While this extra energy can help in a life-threatening situation, or save one’s job by working extra hours, its long-term effects include damage to the immune system, if the spike in cortisol levels doesn’t normalize after some time. It is the reason why people who experience regular stress fall sick easily.

While adults can, fortunately, find ways to reduce stress levels, babies cannot. And if caregivers do not manage these stress levels, continuous and/or high levels of stress can be damaging in the long term.

Absence Of Parents Can Be Distressing

Stressful situations can be unpredictable and/or uncontrollable. For babies, their entire existence is uncontrollable and unpredictable. Considering this, it is very stressful for babies. The only thing that babies can do to gain attention, whether they are hungry or cold, is cry. They cannot survive without their caregivers. Thus, when their desperate cries for attention are not answered, they feel profound powerlessness.

According to neuroscientists, corticotropin release factor, or CRF, also described as a fear hormone is the body’s response to fear and can be linked with the fear babies feel when they are separated from caregivers.

In the journal Biological Psychiatry, a 2002 published study showed higher levels of cortisol among mammals that are separated from their mothers at a young age. Thus, the cortisol levels increased in a squirrel monkey, every time it was separated from its mother. Even if it was only for five hours, the repeated separation led to an increase in its feedback sensitivity, resulting in its behavior changing to being clingier, less playful, and easily distressed. Studies suggest similar results among human babies with high levels of cortisol in early life. Additionally, it can lead to a reduced number of cortisol receptors that help in absorbing cortisol and managing its levels. Therefore, with lesser receptors, the ability of a person to manage stress reduces too.

Moreover, babies that were held by their caregivers and experienced the pleasure of the sense of touch have a higher number of cortisol receptors, thus having an increased capacity for managing stress in adulthood.

Stressed Children Have Stressed Parents

An article published in Biological Psychiatry discussed a study wherein scientists subjected monkeys to ‘unpredictable foraging’ – a process where the mother did not know where the next meal would be from. Considering it was the mother’s duty to find food, it was more stressful than having less to eat. 

However, scientists found that because the mother was often unavailable, looking for food, her young ones did not have her calming presence that helped them relax. Thus, the baby monkeys too had stress hormones flooded in their brains and were in a constant state of anxiety. 

In humans too, a mother’s presence (or lack of) can have a profound biochemical effect on the stress levels in a baby. Often, when the quality of a caregiver’s presence is poor, either due to being mentally unavailable, or having an alcohol addiction, babies, despite being with their biological parents, have higher levels of cortisol and thus stress.

The effect of stressed parents having stressed babies was perhaps seen in a study conducted by University of Wisconsin’s Marilyn Essex in 2002.

She conducted regular tests measuring the levels of stress of a study group of 570 families, between the first five years of the birth of the children in those families. When she measured the children for levels of stress at 4.5 years, she found that children who were currently living with stressed-out mothers had higher levels of stress, only if the mothers had been stressed while they were infants too.

It proved that as compared to babies with happy and easier baby hoods, babies with stressed childhoods are more likely to produce more cortisol under pressure, find it harder to face difficulties in later life, and experience tensions.

Social Deprivation And Depression

Babies that are protected from discomfort and that lead to happy peaceful babyhood, produce more cortisol receptors. However, without this, a baby’s brain develops an overactive stress response. While in the short-term it leads to permanent stress and very high levels of cortisol, in the long run, it could result in an anxious personality.

With more cortisol receptors, the brain can easily clear up the stress hormones, which in turn makes it easier for the brain to stop producing cortisol when it is no longer needed and prevent long-term damage.

When a baby with an overactive stress response system experiences stress, its brain gets over-flooded with cortisol and the cortisol receptors shut down. With the receptors shut down, the cortisol hormones stay in the brain for a longer than intended time, causing damage such as depression in adulthood.

Impairment in the social brain can lead to lesser production of norepinephrine, which is required for concentration and sustained effort. Also, people with depression issues are known to have lower levels of norepinephrine. It is therefore tough for people suffering from depression to stop actions that are harmful.

In addition to these, social deprivation in infancy is also linked with a permanent reduction in dopamine synapses. A child with happy babyhood has a lot of dopamine flowing in its orbitofrontal cortex. It learns new things because it feels positive about them and also learns to adapt to new challenges. But a child that lacks these synapses in the brain will not be able to focus on positive rewards well, will have less adaptability, and be more susceptible to depression.


This makes it clear that the more loved and protected children are in their babyhood, the more likely they are to lead happy adult lives.

Proper growth of the social brain is vital and positive social interactions are instrumental for its growth. Nature – our biochemistry and genes – and nurture – the loving surroundings, caring parents, and attentive caregivers – are both equally vital in shaping the brains and thus the personality of a person. And this shaping takes place right from the time a baby is born.