How does brain development continue from childhood into adulthood?

Brain development is a continuous, lifelong process driven by neuroplasticity, the brain's capacity to reorganize its structure and function in response to experience.12

During early childhood, the brain undergoes rapid growth, forming an abundance of synapses. By age two or three, a child’s brain possesses roughly twice the number of synapses found in an adult brain. As the individual interacts with their environment, sensory inputs reinforce specific neural pathways while unused connections weaken.31

This transition from childhood into adulthood involves a significant "pruning back" of these excess connections, a process that often intensifies during adolescence. Brain development is estimated to continue into the mid-20s, shaped by the ongoing formation of new connections and the strengthening of existing ones. Even in adulthood, the brain remains dynamic; while unused neurons may atrophy, the brain can compensate for functional loss by forming new nerve branches and synapses. Additionally, adult neurogenesis may play a role in recovery from injury or disease, remaining a significant area of stem cell research.321