There has been a great deal of progress in medicine and technology over the past 50 years which has contributed to recent advances in neuroscience and which has brought new clarity and understanding to the field of early childhood brain development. Children are born ready to learn, however, contrary to popular belief, there is no compelling neuro-scientific argument for beginning formal education as early as possible.

Much of the evidence that supports the claim that childhood is a critical period of learning comes from nonhuman primate studies, where increased synaptic connections which have been found to occur in the first three years of life, suggest an important period of learning for monkeys (Gazzaniga, 1995). In humans however, more recent evidence using neuroimaging techniques, argues the opposite may be true. Instead of being a period associated with increased synaptic connections, childhood is a period of synaptic loss – or ‘synaptic pruning’ (where infrequently used connections are removed) and strengthening of existing synaptic connections associated with increasing cognitive capacity (Casey, Giedd, & Thomas, 2000). In addition, we know that structural changes continue well into puberty and throughout adolescence (e.g. Sowell, Trauner, Gamst, & Jernigan, 2002).

Neuroscience has shown the remarkable extent to which the brain is still developing during adolescence, particularly in areas such as the frontal and parietal lobes (Huttenlocher, 1979). In addition, these regions undergo myelination during puberty and myelination increases considerably throughout adolescence (Sowell, Peterson, Thompson, Welcome, & Henkenius, Toga, 2003). Given our increasing understanding of brain connectivity, taken together one might predict that the adolescent brain is less efficient in processes such as: directing attention; planning future tasks; inhibiting inappropriate behaviour; multi-tasking and a variety of socially-oriented tasks.

What are the implications for education? The concept of a critical period or window for learning a particular skill or ability has historically been promoted. However, there is now general agreement that these ‘critical periods’ should be considered as ‘sensitive periods’, suggesting that they are not fixed and rigid but malleable within an environment.

Just as periods sensitive to language acquisition have been linked to synaptic pruning in very young children, evidence for synaptic pruning continuing in adolescence suggests the possibility of sensitive periods here too. For example, research has shown that adolescents activate different areas of the brain compared to adults when learning algebraic equations (Luna, 2004). Overall, what the evidence suggests is that formal education as well as social experience may have a particularly important role in moulding the teenage brain.

'The characteristics of learning readiness are developed rather than taught and only through numerous concrete interactions with the world can a young child prepare to benefit from formal instruction later.'

David Elkind, noted author on child development