Mothers are so important in the first three years of life because this window is the brain's first critical period of development — and the quality of a child's attachment to their primary caregiver during this time literally shapes the physical architecture of their growing brain. According to psychoanalyst and author Erica Komasar, when a mother or primary attachment figure is not physically and emotionally present enough during these early years, the consequences reach far beyond childhood, affecting emotional regulation, stress tolerance, relationships, and mental health well into adulthood.
Why Are Mothers So Important in the First 3 Years?
The first three years are not just an emotional milestone — they are a biological one. During this period, a baby's right brain, often called the social-emotional brain, is developing at a breathtaking pace. This part of the brain governs everything from emotional regulation and stress response to the ability to read social cues and form trusting, loving relationships.
What drives that development? The consistent, moment-to-moment presence of a primary attachment figure — most commonly, the mother. When a baby is distressed, the mother soothes them. When a baby is frightened, the mother regulates their nervous system back to a state of calm. This repeated cycle of distress and soothing is not just comforting — it is neurological training. Over time, the baby begins to internalize the ability to regulate their own emotions.
As Komasar explains, it takes a full three years of this process before a child can begin to genuinely self-soothe. There are no shortcuts, and no amount of high-quality childcare can fully replicate the unique neurological bond between a mother and her child during this formative window.
What Is the Right Brain's Role in Emotional Development?
The right brain — also called the social-emotional brain — is the control center for some of the most essential human capacities:
- Emotional regulation: Keeping emotions from swinging to harmful extremes
- Stress and adversity tolerance: The ability to cope when life gets hard
- Reading social cues: Understanding how others feel and what they need
- Executive functioning and judgment: Making thoughtful, considered decisions
- Trust and deep relationships: The foundation for all meaningful human connection
This part of the brain does not develop in isolation — it develops in relationship. A mother's consistent presence is quite literally the environment in which the right brain grows. Deprive a baby of that consistent environment, and the right brain's architecture is affected in ways that are difficult — and sometimes impossible — to fully reverse.
How Does Early Daycare Affect Baby Brain Development?
One of the most difficult — and important — messages in this conversation is the role of early separation. When mothers return to work at six weeks, three months, or even six months postpartum, babies are placed in daycare before their stress-regulation systems are ready to handle separation.
The key player here is the amygdala — a small, almond-shaped structure in the brain that governs the stress response. In healthy development, the amygdala is meant to remain largely offline during the first year of life. Mothers buffer their babies from stress naturally — in many cultures around the world, babies are worn on their mother's bodies for the entire first year, keeping them physically close and neurologically protected.
When babies are separated too early, large amounts of the stress hormone cortisol flood the developing brain. This is not just uncomfortable for the baby in the moment — it is actively changing the way their brain develops. The amygdala is activated prematurely, setting the brain's stress response to a higher, more reactive baseline that can persist for life.
The antidote is incremental exposure. Small, manageable amounts of frustration and separation — introduced gradually after the first year — help a child develop what Komasar calls a psychic immune system: the internal resilience to tolerate being away from their mother without feeling existentially threatened.
What Are the 3 Types of Attachment Disorders in Children?
When the normal developmental process is disrupted by too-early or too-frequent separation, babies develop what are known as attachment disorders — pathological defensive strategies their developing minds create to cope with the absence of the person who is supposed to be the center of their universe. There are three primary types:
1. Avoidant Attachment Disorder
When the mother returns after an absence, the baby turns away from her. This defensive independence — appearing unbothered or self-sufficient — is the brain's way of protecting itself from repeated disappointment. Of the three types, avoidant attachment is most strongly linked to depression and difficulty forming trusting intimate relationships in adulthood.
2. Ambivalent Attachment Disorder
The opposite of avoidance: the baby becomes intensely anxious and clingy upon the mother's return, unable to let her out of sight for fear of losing her again. This type is most correlated with anxiety disorders in adulthood and similarly impairs the ability to form healthy relationships.
3. Disorganized Attachment Disorder
The most complex and most difficult to treat. In this case, the baby has no consistent strategy — they may turn away, then cling, then express anger, then cycle through all of these behaviors in rapid succession. Disorganized attachment is most strongly associated with borderline personality disorder in adulthood and profound difficulties with relationships and self-identity.
These are not simply personality quirks or phases children grow out of. They are neurological adaptations — the brain rewiring itself in response to early emotional deprivation — and they follow children into every relationship they will ever have.
How Long Should a Mother Stay Home With Her Baby?
The short answer, according to Komasar, is as present as possible for the first three years — and meaningfully involved through age 18. While she is clear that mothers can and do work, the critical distinction is prioritization. A career can be paused, scaled back, or resumed. The first three years of a child's brain development cannot be repeated.
The role of mother does not end at toddlerhood either. A parent continues to serve as what Komasar calls an emotional digestive system — helping children process experiences, feelings, and thoughts all the way through adolescence. Even teenagers who seem not to need their parents desperately need them to be present and emotionally available.
The prefrontal cortex — the seat of judgment, emotional maturity, and decision-making — does not finish developing until around age 25 in women and 27 in men. A mother's presence during the years a child is still living at home is part of that developmental journey.
Why Has Society Stopped Valuing Motherhood and Caregiving?
Perhaps the most culturally urgent part of this conversation is the question of why we no longer honor what may be the most important work a human being can do. Komasar describes a painful but common experience: mothers who identify themselves at social gatherings as full-time caregivers or homemakers — and are met with turned backs and disinterest, even from other women.
This is not a minor social slight. It reflects a profound cultural shift in which nurturing, caregiving, and emotional labor have been systematically devalued — relegated to poorly paid workers and framed as something that gets in the way of a woman's "real" contributions.
But historically, women were what Komasar calls the keystone species of society — the nurturers who cared for children, the elderly, the sick, and who provided the emotional foundation on which communities were built. When that role is dismissed, the emotional health of the entire society suffers.
The solution is not to tell women they cannot have careers. It is to restore the cultural understanding that mothering is a career — one that demands intelligence, sacrifice, creativity, and emotional depth, and one whose returns compound not just in a single family, but across generations.
If you are a mother, a primary caregiver, or someone who supports one: what you are doing matters more than almost anything else in the world. The science says so. The children — even if they can't articulate it yet — know it too.
