From birth to age 5, a child’s brain develops more, and more rapidly, than at any other time in life. And while genetics plays a significant role, scientific research has made clear that the quality of a child’s experiences in the first few years of life – positive or negative – helps shape how their brain develops. And that these experiences have lasting impact on their health and ability to learn and succeed in school and in life.
90% of a Child’s Brain Develops By Age 5
The human brain, the command center of the entire body, is the only organ not fully developed at birth. At birth, the average baby’s brain is about a quarter of the size of the average adult brain. Incredibly, it doubles in size in the first year and keeps growing to about 80% of adult size by age 3 and 90% – nearly full grown – by age 5.
A newborn baby has all of the brain cells (neurons) they’ll have for the rest of their life, but what really makes the brain work – and enables us to move, think, communicate and just about everything else – are the connections between those cells. And the early years of a child’s life are a crucial time for making those connections – at least one million new neural connections (synapses) every second, far more than at any other time in life.
Different areas of the brain – which are responsible for different abilities like movement, language and emotion – develop at different rates. Eventually brain connections connect with each other in more complex ways, enabling the child to move and speak and think in more complex ways.
Brain Development = Child Development
All children develop differently – some will walk or talk earlier than usual, while others may take more time – but it’s clear that the early years are the best opportunity for a child’s brain to develop the connections they need to be healthy, capable, successful adults.
Recent scientific research has shown that the connections needed for many important, higher-level abilities – like motivation, self-regulation, problem solving, communication and self-esteem – are formed in these early years. Or not formed. And it’s much harder for these essential brain connections to be made later in life.
How Brain Connections Are Built
Starting from birth, brain connections are built through a child’s everyday experiences – by positive interactions with their parents and caregivers, and by using their senses to interact with the world around them. It’s a young child’s daily experiences – the amount and quality of care, stimulation and interaction they receive in their first days, weeks, months and years – that determines which brain connections develop and will last for a lifetime.
Caring, Responsive Relationships
The most important influences on a child’s development are their relationships with the adults in their life. Loving relationships with warm, responsive, dependable adults are essential to a child’s healthy development. These relationships begin at home, with parents and family, but also include child care providers, teachers and other members of the community.
From birth, young children serve up invitations to engage with their parents and other adult caregivers in their lives. Babies do it by cooing and smiling and crying; toddlers are able to communicate their needs and interests more directly. Each of these little invitations is an opportunity for the caregiver to either be responsive or unresponsive to the child’s needs. This "serve and return" process is fundamental to the wiring of the brain. Parents and caregivers who give attention and respond and interact with their child are literally building the child’s brain. That’s why it’s so important to talk, sing, read and play with young children from the day they’re born, to give them opportunities to explore their physical world, and to provide safe, stable and nurturing environments.
Studies have shown that babies who experience more of these types of positive interactions will go on to be healthier and more successful in school and in life. Unfortunately, the opposite is true as well. Young children who are deprived of caring interaction do not develop as many brain connections, and that has negative, lasting impact.
Poverty, exposure to family violence and lack of access to quality early learning experiences are all factors that can negatively impact a child’s early development, and subsequently, their long-term success.