Our students are working harder than ever and they think it's good to work hard

John Kerr, Edexcel

Teachers were less likely (45%) to say standards had improved through children's hard work.

Fiona Johnson, of the MORI Social Research Institute, said: "Our findings indicate high levels of confidence in the exam system amongst its key stakeholders - teachers, students and their parents.

"Motivated young people are working hard - probably, in fact, harder than ever - and our respondents strongly believe that it's this, rather than any 'dumbing down', which accounts for their success."

The survey contradicts the perception that teenagers do not think it is cool to study and worry about being considered nerdy if they are studious.

Teased

Among GCSE students questioned, three-quarters (75%) said they would not be teased by friends if they were seen to work hard at school.

Among pupils studying for AS-levels, the figure rose to 86%.

The chief executive of Edexcel, John Kerr, said: "This poll confirms what many of us in the education sector already believe - that our students are working harder than ever and they think it's good to work hard.

"This is one of the most extensive studies of its kind of students, teachers and parents.

"Commitment to qualifications across all these groups is extremely encouraging."

For the poll, MORI questioned more than 2,500 students, teachers and parents in England and Wales between February and August this year.