Perhaps one of the most important discoveries of cognitive and learning sciences, and one that contradicts a long-held belief, is that the brain is much more adaptive that was previously thought. When I was a student in the 1980’s, it was believed that brains developed through one’s youth, but that developed slowed in adolescence and stopped in adulthood.
While our new knowledge of brains does give a more detailed understanding of brain development, we have also discovered the importance of development on brains. A range of environmental factors (including both physical factors and cultural factors) can affect brain development, and healthy brains must progress through their developmental stages, such as building connections in youth followed by pruning on those connections during adolescence.
One aspect of brain development that has newly-discovered importance is its response to learning. Learning tends to be a brain-wide activity and despite learning affecting structure and function of localized neurons, learning typically engages multiple parts of the brain, and what was used for one purpose can be recycled for another purpose later. In these ways, the brain is a more plastic organ than previously thought.
While some types of learning are easier at different times in life, the recent discoveries do suggest that the human brain can learn throughout adulthood. Good teachers recognize this, recognize the type of learning that is most appropriate and organize their lessons to reflect what is needed.