After analysing start dates around the world, Christine Stephen of Stirling University concludes that there is no right age for launching into a formal school career. Even starting at seven does not disadvantage children, Dr Stephen states in the latest Insight publication on early years education.
Six or seven is the average age for starting, one international review points out, but Northern Ireland has recently moved to four, as has the Netherlands as part of its early intervention strategy.
Countering that is a move in Queensland, Australia, to start school at six and offer all five-year-olds a full-time preparatory year. But Dr Stephen states: "These policy variations cannot be endorsed by research findings."
American evidence on readiness for school shows that teachers, parents and children have different views of the skills and knowledge required and test results are unreliable. She states: "There are no consistent results from studies examining the benefits of delaying school entry."
Scottish studies, Dr Stephen continues, have found "enormous variations" in cognitive development when children start school and little relationship between the amount of pre-school experience and their baseline assessment.
This conclusion is not shared in England.
One option is to increase the flexibility parents have and allow them the option of another year in early education for their child.
But Dr Stephen adds: "An alternative is for children to move to primary school in accordance with established age patterns, but to be grouped with others with similar starting points to experience a highly differentiated curriculum and pedagogy (in the first year at least) that allows for learning opportunities to match children's needs."
She believes there is international recognition for a distinct 3-6 phase of education and widespread support for early years education as a means of helping disadvantaged children. It makes a difference to cognitive, social and behavioural development.
Early Years Education: Perspectives from a Review of the International Literature is available on the Scottish Executive publications website.