Our nervous system does not calm down on its own. From the very first days of life, it learns to do so through contact with another, already calm nervous system. This need for another in order to regain our balance is not a weakness or a lack of willpower: it is a biological fact, written into us from birth. And contrary to what we often believe, it never entirely disappears.<\/p>\n
A newborn has no way of regulating its internal states. This inability is not a quirk of nature: it is physiological. The prefrontal cortex, the region of the brain that allows us to modulate emotions, is the last to reach maturity. Its myelination \u2014 the formation of the sheath that surrounds nerve fibres and makes the transmission of impulses efficient \u2014 begins after birth and continues for years, into adulthood. In other words, the infant's nervous system is simply not yet equipped to regain its balance alone.<\/p>\n
When overwhelmed \u2014 by hunger, fear, tiredness, the unknown \u2014 a baby therefore needs an adult whose presence, voice and face will, quite literally, soothe its nervous system.<\/p>\n
The psychologist Edward Tronick made this mechanism visible through an experiment that has become famous: the \"still face\" paradigm, designed in the late 1970s. The set-up is simple: a mother interacts normally with her baby, then, on cue, abruptly stops all expression and holds a neutral, motionless face; after a while, she re-engages.<\/p>\n
What we observe is striking, and it repeats from one baby to the next. As long as the face stays frozen, the child first tries to re-establish the connection \u2014 smiling, reaching out, calling \u2014 then, failing to do so, becomes disorganised: it grows agitated, turns away, and finally cries. And the moment the mother becomes present and expressive again, the child settles. The baby does not calm itself: it regains its calm through contact with another nervous system, one that is already regulated.<\/p>\n
This mechanism has a name: co-regulation. A still-immature nervous system attunes to a mature, calm nervous system, and through that contact finds a balance it cannot yet produce on its own.<\/p>\n
The neuroscientist Allan Schore has shown how fundamental this process is. In his work on affect regulation and attachment, he describes attachment itself as the dyadic regulation of emotion: the infant relies on the parent's nervous system to interpret its own sensations and modulate its distress. These exchanges, repeated thousands of times, are not merely tender moments \u2014 they shape the developing brain.<\/p>\n
The researcher Ruth Feldman, for her part, measured this coordination. In a study where mothers and their three-month-old babies interacted face to face while their cardiac activity was recorded, she showed that their heart rhythms synchronised within less than a second \u2014 and that this concordance increased during moments of shared gaze, voice and emotion. Two bodies in connection quite literally attune their heartbeats.<\/p>\n
What makes this idea robust is that different teams, using different methods \u2014 filmed observation with Tronick, the neurobiology of attachment with Schore, the measurement of physiological synchrony with Feldman \u2014 arrive at the same conclusion. Early in life, the human nervous system regulates in twos.<\/p>\n
As we grow, something precious happens. Through repeated experiences of shared soothing, the child internalises them and gradually develops its own capacity to regulate. This is what we call self-regulation: being able, on one's own, to regain calm after an upset.<\/p>\n
But this self-regulation never entirely replaces the need for others. As adults, we continue to regulate ourselves through contact with others, often without realising it: a beloved voice that is enough to ease the tension, a quiet presence that soothes without a word, a look that reassures. The need for another in order to regain calm does not vanish with childhood \u2014 it softens and transforms, without ever disappearing.<\/p>\n
Polyvagal theory, proposed by the neuroscientist Stephen Porges, offers one way of explaining this phenomenon by linking it to the role of the vagus nerve and to the cues of safety our nervous system picks up in others. It is an illuminating contribution \u2014 among others \u2014 to the understanding of something that observing an infant had already made obvious: we are beings made for connection.<\/p>\n
We live in a culture that prizes autonomy, the ability to \"manage on one's own\", to depend on no one. This idea has its value, but it tells an incomplete story. From the very first day of our lives, our inner balance is built, and rebuilt, within relationship. Needing a presence in order to settle is not a flaw to be corrected: it is the mark of our deeply social nature.<\/p>\n
We are not made to regulate ourselves alone. We never were.<\/p>\n