It has become an accepted truth among educationalists, governments and academics: poverty, poor parental education and lack of access to books at home are some of the biggest barriers to pupils' academic success.
Now, though, there is evidence that teachers disagree. A National Foundation for Educational Research opinion poll found that the profession actually rates poverty as among the least of their pupils' potential problems.
Teachers were given a list of 18 possible barriers in education. Asked to list the ones that most "limited students' ability to realise their full potential", just 16 per cent cited poverty, which finished as only the 12th most important factor.
"Poor access to education resources outside of the classroom" finished even lower and was listed as a problem by just 15 per cent of the 1,567 teachers surveyed.
And although many believe that educational expectations are passed down the generations, just a fifth of the teachers - who came from 1,211 primaries and secondaries - thought that parents' education could be a barrier to their child's achievements.
But while teachers view the education and wealth enjoyed by their pupils' families to be of limited consequence, they see the attitudes of parents and the way they rub off on pupils as crucial. The biggest single barrier to pupils succeeding at school was identified by teachers as "lack of parental support", cited by three-quarters of respondents.
Lack of aspiration was seen as the second most important factor, listed by 54 per cent of teachers, while low self-esteem came in third with 46 per cent.
The results pose interesting questions about how schools should implement a key coalition education policy, the pupil premium, which is currently channelling #163;1.25 billion into schools through an extra #163;630 attached to every pupil on free school meals. The figure is set to double to #163;2.5 billion a year by 2015.
Kenny Frederick, head of George Green's School on the Isle of Dogs, East London, where 59 per cent of pupils claim free school meals, cast doubt on the survey's findings, saying there was a straightforward link between poverty and pupils' educational difficulties.
"If you have pupils coming to school hungry or who haven't got a decent place to sleep, then of course that is going to have an influence," she said. "It is common sense."
Other factors that the surveyed teachers viewed as more important than poverty included "lack of effort" in fourth place, cited by 38 per cent.
It was followed by "poor attention span" and "poor basic literacy", both mentioned by a third of the teachers. Ms Frederick agreed that literacy was a major factor, but argued that it was impossible to separate out factors such as poverty, aspiration and parental education. "They are all interlinked," she said.
Professor Mel Ainscow, from the University of Manchester, said: "The effect of poverty in schools is so powerful that it is worrying if teachers are not identifying it.
"Teachers can interpret pupils' performance in terms of their own characteristics. They will construct explanations around pupil aspiration and low motivation, whereas these things are products of their circumstances."
Most cited factors
Lack of parental support - 75%
Lack of aspiration - 54%
Low self-esteem - 46%
Lack of effort - 38%
Least cited factors
Poverty - 16%
Poor access to resources outside classroom - 15%
Poor basic numeracy - 15%
Lack of careers guidance - 3%.