Fewer than a third of GCSE pupils picked subjects because they liked them, and less than half allowed their academic strengths to influence their decisions, a MORI opinion poll for the Government has found.
Half the 3,500 pupils questioned picked the exam subjects they believed would help them get a job.
Parents had the greatest influence on teenagers' GCSE choices with nearly two in three pupils saying they took their advice. Pupils took less notice of teachers' views but 40 per cent said their choices reflected a teacher's guidance.
Only one in 10 respondents said a school careers adviser would influence their decision, around the same number who consulted their older brothers and sisters. Nearly one in 10 was influenced by their classmates' choice of GCSEs.
The survey was conducted on behalf of the Qualifications and Curriculum Authority. A spokesman for the quango said the findings were a snapshot of how pupils view their aspirations and abilities in the years before GCSE.
Nearly half the respondents believed the choice of GCSE was just as important as high scores and one third criticised the selection on offer at their school.
Pupils had an accurate grasp of their likely performance in individual GCSEs, MORI interviewers found. The number who told researchers they expected to get at least a grade C in each of maths, English and science almost exactly reflected the national rate for each subject.
However, few pupils anticipated wider failure: only 2 per cent of respondents said they did not expect to get at least one C grade or better across the three subjects although, according to last summer's GCSE results, around 60 per cent could expect to do so.
The survey was based on 3,529 questionnaries completed by pupils aged 11 to 16 in 142 secondary schools in England and Wales.The questionnaires were completed during supervised classroom sessions with MORI interviewers in January and February this year.
A QCA spokesman said: "We put these questions on MORI's regular Schools Omnibus survey to get a snapshot. This was part of the preparatory work on the curriculum review."