“If you’ve never had the opportunity to play the piano, how do you know if you’re going to be the next Beethoven or Bach?” she asked.

Ms Smith believed opportunities were vital in releasing pupils’ full abilities, along with passion and enthusiasm. Studies of the brain showed that pupils who did well in certain activities were passionate about them. The concept of emotional intelligence was therefore vital.

She added: “There are just as many pupils with ability in every school in Scotland as there are in any other. You do not have concentrations of ability. What you might have is a concentration of attainment because some children have all of the social context that allows them to demonstrate ability. Everything is for them.

“They have opportunities, encouragement, stress levels that are fairly low. Therefore when they come to school they re well able to demonstrate their abilities. There are other children in other schools where everything militates against them demonstrating their abilities but it does not mean they do not have them,” Ms Smith said.

Old notions of IQ still lingered and ignored the research on multiplicity of intelligences and importance of environmental influences. “The evidence comes up again and again that schools and teachers make a difference,” Ms Smith emphasised.

Some children identified as particularly able were able at a specific activity and not necessarily very able in inter-personal and visualspatial skills, she continued.

Some children’s needs are always better met in a specialised setting, according to Capability Scotland, which runs three special schools. Marie Thomson, head of Westerlea school, Edinburgh, backed inclusion in mainstream schools but said it was not suitable for all. “It can be a socially isolating experience and that can harm a child’s development,” she said.