Children who are born in the summer months may perform significantly worse in school and have lower well-being than those born in the autumn.
This is according to research carried out in England by the Institute of Fiscal Studies (IFS), which claimed the impact of being one of the youngest pupils in an academic year could stay with individuals throughout their life.
It found summer-born children aged seven are between 20 and 30 percentage points more likely to be regarded as below average by teachers in reading, writing and maths skills.
They also score lower in national achievement tests and have less confidence in their academic ability, the study stated.
It suggested this may impact the choices they make for their further education and later careers.
Co-author of the report and research economist at the IFS Ellen Greaves added: "We find evidence that, particularly at younger ages, summer-born children are more likely to report being unhappy at school and to have experienced bullying than autumn-born children."
Meanwhile, it has been claimed by Dr Helen Wright, president of the UK's Girls' Schools Association, that single-gender education can help give both girls and boys greater self-esteem.