In the study, which involved 164 nine to 11-year-old pupils at Glasgow primary schools, children were asked to work in groups of three on scientific experiments involving the transfer of heat.

Christine Howe, of Strathclyde University’s Centre for Research into Interactive Learning, said: “There is a great deal of emphasis on experiments to get children to understand a scientific interaction. But what we found was that the talk was much more important than feedback from experiment results.”

Experiments should be used to give the children “a scaffold for their talk”, she said. Dr Howe added: “They have to engage in constructive dialogue. It won’t happen by accident. Highly structured workbooks have to be provided. We’re not telling the pupils what to say but what they should talk about at each stage.”

The study is the final one in a series of 15 carried out on behalf of the Economic Social Research Council.

Another study for the ESRC, presented at the conference by David Warden and Donald Christie, of Strathclyde University’s psychology department, showed how a carefully structured personal and social education course led by teachers could reduce levels of bullying.

It involved 160 primary 5 pupils from 14 schools who were divided into groups depending on their levels of social competence and moral understanding, and whether they were bullies or were victims of bullies.

Measured against a control group, the course did develop more awareness of other people’s feelings, Dr Warden said. Although there was no scope in the study to prove that behaviour had changed, Dr Warden advocated structured PSE activity in primary school classes.

“PSE is supposed to have a regular place in the curriculum - but all too often it is squeezed out. Children are therefore not given the space to consider emotional matters,” he said.