The best way to understand how a child develops resilience is to look at the role of the nervous system vis-a-vis the rest of their body. Knowing how the child's brain reacts to stress can help us understand what they need in order to develop empowered and adaptable responses to life's unpredictabilities.
It is significant at the outset to note that in the embryo stage, the nervous system begins as the ectodermal layer of a three-layer group of cells, developping into a tube shape that migrates inward as the embryo forms. In other words, the nervous system starts on the outside and migrates inward. Neuroscientist and mindfulness researcher Dr. Daniel Siegel points out,
This origin of neurons, the basic cells of the brain, on the "outside" and their journey "inside" the body developmentally reveals a philosophical point that the brain originates at the interface of the inner and outer worlds of our bodily defined selves. When we think of the mindful brain, it is helpful to keep this inner/outer interface in mind (Siegel, pg. 29, 2007)
Similarly, our stressors can be inside us- such as a stomach ache right before going on stage to perform, as well as outside us, like when we see a person we don't like approaching us for a conversation. Just as the nervous system takes in information from both sides and sends it up to the brain, so when we meditate, we scan both our thoughts about the external world and the effect they have on our body, soothing the nervous system as we go.
The ability to observe ourselves under stress and have an awareness of our reactions, though, is a skill that is unique to the human pre-frontal cortex; it is the difference between having both a brain and a mind, versus simply having a brain. Contrary to most of the animal kingdom, when human babies are born, they still have 70% of their brain to develop [Source], and at birth, the pre-frontal cortex itself is still very much developping; in fact, at birth, infants are making between 700 and 1000 synaptic connections per second [Source]. One important part of the brain that is fully formed at birth, though, is the amygdala, which is the alarm system of the brain that takes in information about danger, and prepares our body for the fight or flight response.
Evolutionarily, the limbic brain, made up of the amygdala, the hippocampus, the thalamus, along with a few other other structures, was the first part of the mammalian brain to develop. Its alarm system came in handy if ever we found ourselves stalked by predators or other such dangers, upon which occasion, the sensory information would travel from the ears or eyes to the thalamus, and finally to the amygdala. The small, bilateral set of structures equidistant between the ears then secretes a course of stress hormones that put the body on high alert. The pupils dilate to let in more light, the hearing becomes more acute, the heart pumps more blood to the limbs to prepare them for fighting or fleeing, while restricting blood flow to the digestive system, a superfluous mechanism in a life-or-death scenario. [Source]
As babies, when we experience distress like having a wet diaper, for example, our amygdala goes through the same procedure, flooding our bodies with stress hormones such as the catecholamines [epinephrine (adrenaline) and norepinephrine (noradrenalines)] and eventually cortisol (Kabat-Zinn, pg. 312, 2013). In response, we begin to fuss or cry to attract the attention of our caregiver, another mechanism evolutionarily designed to ensure the survival of our species.
It turns out that evolution has made the work relatively easy to come up with an appropriate response to the cry of a baby. Eradicating the need for all others, all we typically have to do to calm a baby is to change their diaper, feed them, or pick them up and hold them. Babies are biologically programmed to calm down when they're picked up [Source] as it stimulates a parasympathetic response from the vagus nerve, a major nerve runs from the cerebellum to the belly, impacting all organs of the body along the way. This is the same relaxation response we get when we meditate; we are relaxing the cerebellum, which signals to the vagus nerve to relax our internal organs.
Babies show a ingrained tendecy to want to connect with their mothers. Loving eye contact with the mother is a highly satisfactory experience for the baby, and it does double duty by spilling synapse-building chemicals into their system.
From the earliest moments of life, parental nurturance shapes the child’s emotional make-up, literally altering the course of brain-growth. One of the key elements of secure parent-child attachment is affectionate eye-contact. A parent’s sustained, loving gaze and smile suffuses infants with indescribable joy. What ensues is a cascade of dopamine, endogenous opioids, enkephalins and endorphins in the baby’s brain- all feel-good
chemicals associated with loving relations. This joy-precipitated surge of brain chemicals promotes the maturation of precise regions of the cortex, which are concerned with healthy regulation of emotion later in life. Every baby requires this kind of nourishing experience regularly and frequently, for healthy brain development [Source].