Success stems from a sense of purpose based on moral and ethical values, say advisers.
How good is the spiritual capital of your school? This is a question all schools should ask themselves - and it is the key to success, according to a study by two influential education researchers.
Spirituality is not simply an issue for faith schools, even though that is the way it is widely perceived.
Studies by David Egan, special adviser to the Welsh Assembly government until last year, have found that successful schools all had a sense of purpose informed by strong belief systems and moral and ethical values.
"The term spirituality is something we associate with faith schools or what schools do through RE," he said. "But what I found is that they see it as part of how they operate, part of their educative purpose, and it seems to be a key part of their success."
Professor Egan's findings are based on a study of five successful but diverse state secondary schools in Wales as part of a major international study into school improvement. Only one of the five was a faith school, but he concluded that in all cases the schools' "spiritual capital" was a crucial factor in their exam and inspection successes.
Professor Egan's comments were given at the North of England Education Conference in Cardiff last week, where David Hopkins, the conference president, talked about the need for a moral purpose in schools. He told The TES that it was the same thing as spiritual capital.
Professor Hopkins, a former professor of education and chief adviser on school standards for the Government, said schools that led with a moral purpose ensured that all pupils succeeded to their potential and did not just do what was needed to meet targets. But he said a large minority of schools in England had still not achieved this.
"Lots of schools have the rhetoric," he said. "[Fewer] have the educational ability to put it into practice, although we are seeing it increasingly."
He said schools with moral purpose were those where heads could link their vision to practical action. Plans underpinning that vision could be seen being carried out in the classroom.
Asked for an example of spirituality in a school, Professor Egan, from the University of Wales's Cardiff School of Education, talked about a secondary where three girls who had just completed their mock GCSEs were killed in a car crash.
"It was half-term but the head went and opened the school up," he said. "All the children came into the school, and many of the teachers. That seemed to be absolutely symbolic of the type of community they had created."
He defined a school's spirituality as having a strong ethos, a refusal to accept low performance, strong relationships, a strong pupil voice and student self-confidence.
Other factors in the five schools' success included careful financial monitoring, links with primaries, innovation, good use of support staff and investment in pedagogy.
When asked if there was a "silver bullet" for improving school performance, Professor Egan said he agreed with a report by Sir Michael Barber, the former Downing Street adviser, written for McKinsey, the global consultancy firm, which said that the quality of teachers was crucial.
But Professor Hopkins said he found the Barber research irritating as "it is just a counsel of perfection - it doesn't help you deal with failing schools like the Ridings".
"It's down to the semantics of how you define spiritual. Yes, I think schools should have a bit of spirit - a sense of positive virtue does a school no harm. I'm sure schools do their best to make pupils optimistic about life, helpful to others and with a purpose to their own life."
Tony Storey, head of Hayfield School in Doncaster
"Schools do need strong moral and ethical values and to go beyond material sensitivities and recognise that things like the arts can exist on a different plane.
"But the use of the word spiritual is too open to being hijacked by those with a proselytising religious agenda." Keith Porteous Wood, executive director of the National Secular Society
"People find motivation in all sorts of places. One size doesn't fit all. We're big on rights, responsibility and respect - getting people to appreciate that no man is an island. A "what's-in-it-for me?" attitude doesn't help anyone. It's our way of addressing the spiritual and moral vacuum in modern society.
Eddie Izzard, head of Winklebury Junior School in Basingstoke.