Brain Development

Early childhood matters because early experiences shape the architecture of the developing brain, establishing a foundation for all future learning, behavior, and health.

In the first five years, the brain develops more, and more rapidly, than at any other time of life. By age two or three, a child’s brain will have up to twice as many connections (synapses) between brain cells (neurons) as it will have in adulthood. These extra connections make the brain both highly receptive to learning and highly vulnerable to neglect or adversity. When synapses are activated, they become stronger. When rarely used, they become weaker and gradually disappear. And when children experience trauma or repeated stress, the brain’s development can be critically damaged – leading to lifelong challenges in learning, behavior, and health.

90% of brain growth happens before kindergarten

How can we ensure that a child’s brain is wired for success? The most important foundations for optimal brain development are a healthy body and a reliable, nurturing relationship with at least one caring adult. Even children who experience serious adversity can achieve positive outcomes with the right care and support. When equipped with knowledge and resources, a parent or caregiver can help a child cope with challenges, build resilience, and develop the skills and attitudes necessary for a healthy, productive life.

More than one million new neural connections are formed every second during the first few years of life.

Serve and Return

We know that regular, responsive interactions between young children and their caregivers are essential to the developing brain. New research tells us that these acts of “serve and return” also produce observable changes in the brains of parents and caregivers, making the early years a formative period for both children and adults.

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  1. Center for the Developing Child, Harvard University. 2021.