Dr Fisher was addressing the Scottish Network for Able Pupils at Glasgow University's Bearsden campus, where the initiative is based. He said that when able children are forced to articulate their own thinking and translate that for others, the less able benefit from having a model of elaborate and reasoned argument that supports their thinking.
"Listeners are still fulfilling an important function," Dr Fisher said. "They internalise ways and expectations for participating in that kind of higher level discussion." Able pupils should be a key part of a "community of inquiry" in classrooms.
Teachers should attempt to "expand the consciousness" of the able pupil by presenting a variety of viewpoints on any particular topic. Pupils should be encouraged to look at things in different ways and consider different uses, and able pupils should be asked to supply more than one explanation or reason.
But Dr Fisher warned that children also need to be stimulated by activities such as writing, talking, reading and problem-solving. "The brain is always looking for an easy life," he said.
He praised the 5-14 curriculum for having the flexibility to allow teachers to exercise their judgment, "unlike other more rigid forms of national curriculum". This should help Scottish teachers to build a "thinking approach". But raising achievement meant adding value to very good teaching as well as routine teaching.
Teachers may, however, have a problem in recognising their own good work, according to one of the conference speakers. Willi Bremner, depute head at Boroughmuir High in Edinburgh, said his last two years as development officer for a national project on "promoting social competence" among pupils had shown him that Scotland's efforts in this field were "world class".
Yet a lack of awareness on the part of teachers meant they often found it easier to plug into developments in the United States, Canada and Australia. "With the number and range of developments ongoing at the moment and the quality of teacher input," Mr Bremner said, "Scotland should be a world player in the area of personal and social education."
But initiatives built up from the grass roots, such as peer support projects for pupils at Oban and Perth high schools, had found it difficult to attract national funding. The "top-down" approach should not be the only model.
Mr Bremner said one resource for PSE was the virtual teachers' centre website. "At the moment, it is gathering dust. It won't be developed unless there is a cry from teachers saying it is important."