Development occurs in several ways. That means that much of its hard wiring is shaped by the experiences that people have. In part, there are predetermined sequences of development in childhood, including windows of opportunity for laying down the basic hardware necessary for later learning. That is why new languages as well as the arts ought to be introduced to children very early in life. And finally, in many respects there is no limit to growth and to the capacities of humans to learn more.
Neurons continue to be capable of making new connections throughout life.
It then becomes less flexible, and reverts to primitive attitudes and procedures. That is why we must create and maintain an atmosphere of relaxed alertness, involving low threat and high challenge. The essential element of perceived threat is a feeling of helplessness or fatigue. Occasional stress and anxiety are inevitable and are to be expected in genuine learning. The reason is that genuine learning involves changes that lead to a reorganization of the self.