The debate on the age that children start school in Scotland should be re-opened, according to an expert.
Boys may benefit from starting school later than girls
Research by Glasgow City Council has found that boys in particular could be put off learning for life if they go to primary school before they are ready.
Children and teachers in 50 primary schools were involved in the study.
The author of the report - educational psychologist Alan McClean - said no child should start school before the age of five.
He also suggested that boys start school at the age of six, a year later than girls.
Mr McLean said: "This is just one of many suggestions I have put forward. We need to think radically.
"I am not suggesting that this should actually happen, but I think it should be open for debate.''
The expert added that children should have a staggered start to school, only entering once they reach the age of five, but only if it is taken in context.
He said: ''I have identified an issue but should not be expected to solve it. We should be looking at what is done in other countries."
Judith Gillespie, of the Scottish Parent Teacher Council, agreed that a debate on the age question should be held.
She said: "Crucially, it has to be ensured that there is no economic disadvantage to them [parents] if they do take the option of deferred entry.
"The current position is that free nursery provision is only for two and a half hours each day, whereas school is free for five hours a day.
"This can actually influence a parent's decision."