THE less jurors know about DNA science, the more likely they are to be swayed by it and find an accused person guilty, research has shown.

Known as the ''white-coat syndrome'', this tendency to be overwhelmed by experts could mean there is a danger jurors place undue weight on scientific evidence.

But a 20-minute presentation to jurors significantly increases their understanding of DNA and its use in criminal trials, and will make them more sceptical and reduce the likelihood they will convict. These are the findings of a study to be released by the Australian Institute of Criminology today.

''The greater understanding increases their objectivity about the evidence of the experts. When there is greater understanding of the evidence, there are fewer miscarriages of justice,'' said the lead researcher, Jane Goodman-Delahunty.

Even defence lawyers and judges were caught by this, she said. ''I think because DNA evidence has attained a status where the underlying science is no longer so controversial that many defence lawyers no longer challenge it and show its fragilities,'' she said.