The brain begins to mature even before birth. Although it continues to mature throughout most of life, the brain does not mature at the same rate in each individual.
This should not be surprising. After all, our bodies grow at different rates — we reach puberty at different ages and our emotional maturity at different times as well. Why should our brains be any different?
Just because you have a classroom full of students who are about the same age doesn’t mean they are equally ready to learn a particular topic, concept, skill, or idea. It is important for teachers and parents to understand that maturation of the brain influences learning readiness. For teachers, this is especially important when designing lessons and selecting which strategies to use.
http://www.apa.org/education/k12/brain-function.aspx
