Staying on at school for an extra year can significantly boost adults' mental ability well into old age, a new research has revealed.
Staying in education longer makes people smarter and results in better memory later in life, it was claimed.
But the research, based on an analysis of adults who left school in the 40s, says that extra tuition fails to make people happier.
The disclosure comes amid mounting pressure on young people to stay in school, college or on-the-job training for longer.
From next year, the education leaving age in England increases from 16 to 17, while teenagers will be required to remain in some form of training to the age of 18 from 2015.
"There seems to be, even when we control for other factors, a distinct jump in the mental abilities of those who went to school for an extra year," the Telegraph quoted Prof James Banks, of Manchester University and the Institute for Fiscal Studies, who co-wrote the report, as saying.
The study was based on an analysis of 12,000 people who left school in the 40s when the leaving age was increased from 14 to 15.
Researchers divided them into two groups, those who left school before the increase in 1947 and those who stayed on an extra year, and subjected them to cognitive tests and questionnaires.
Data was collected every two years between 2002 and 2008.
The findings revealed a link between staying in school longer and having a better memory and mental abilities in old age.
The authors suggest that these adults were more likely to have better job prospects and more mentally demanding professions, which could benefit their mental abilities later on.
But the study found no "statistically significant" effect on well-being or quality of life.
Prof Banks said that the findings might not necessarily be the same for today's youngsters.
The study is published in the official journal of the Royal Economic Society.