The brain reaches approximately 90% of its full weight by the age of 5 years.
While brain development begins in utero and continues into adulthood, the most rapid period of growth occurs in early childhood. By 2.5 years, a child's brain has already achieved about 75% of its adult weight. The subsequent growth between 2.5 and 5 years brings it to approximately 90% of its complete maturation regarding weight. The remaining growth is more gradual; the brain reaches roughly 95% of its final weight by age 10.
Here's a simplified illustration of brain weight development:
| Age (Years) | Approximate Percentage of Adult Brain Weight |
|---|---|
| 2.5 | 75% |
| 5 | 90% |
| 10 | 95% |
It's important to note that while weight is a measure of brain size, it doesn't fully reflect the complexity of brain development. Synaptic connections, myelination, and overall brain organization continue to evolve well beyond the age of 5, influencing cognitive abilities and behavior throughout life.
