Girls outshine boys when it comes to spelling
They are likely to call themselves "excellent spellers" - not realising they get things wrong.
Young men are the worst offenders, but even the young women think they spell better than they actually do.
More than one thousand people aged over 15 were asked to spot spelling mistakes in a piece of writing.
Yet seven out of 10 of the group had described themselves as being good at spelling.
Girls spotted about 67% of the mistakes, while boys managed to spot only 54%.
The study was carried out for the publishers Bloomsbury by Professor Loreto Todd of Ulster University.
She told the Times Educational Supplement: "We used everyday words that schools focused on.
"It wasn't as if we were asking the youngsters to spell 'idiosyncrasy' - we all ought to be able to get 'receive' right."
She said the survey suggested that as many as 15% of young people aged 15 to 21 were "functionally illiterate".
"Being able to spell and recognise words is perhaps more important now than at any time in the past," she said.
In the survey, the younger generation were put to shame by older people.
In one test, people were shown the same word spelt three different ways.
Of those aged between 41 and 50, 90% picked the correct versions, compared with just 65% of those aged between 15 and 30.
From September, the government is extending its literacy strategy to England's secondary schools in an attempt to improve the performance of children aged between 11 and 14.
A spokeswoman for the Department for Education and Skills said: "High levels of literacy are crucial to the economic and social well being of this nation - that's why we have focused on improving reading and writing standards in our schools.
"Last year 99% of all 15-year-olds in schools who took GCSE English passed it and have the equivalent of functional literacy or above.
"We are also working to raise skills among adults. The new family literacy and numeracy strategy is backed by £10m and is working to help parents and their children improve their literacy and numeracy skills."