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.
People failed to appreciate the potential for laboratory error or contamination and for DNA to be accidentally transferred, she said.
Also, the concept of ''random match probabilities'' - the likelihood of a coincidental match between the crime scene sample and a person - was poorly understood, and people forgot to consider that in some places the matches were based on only eight points of comparison, while in the US up to 13 points were matched, increasing the reliability.
Last October a burglar's conviction was overturned in Wyong Local Court after the mishandling of samples in the laboratory caused a false match.
Victoria has had problems with contaminated DNA which led to a temporary ban on its use, while South Australian authorities reported a computer glitch but argued it was unlikely to put any convictions in doubt.
The research by Professor Goodman-Delahunty has also found that frequent viewers of CSI-style television shows are among people with the lowest understanding of DNA science.
People with low understanding of DNA convicted at a rate of 75 per cent in mock trials, while those with greater knowledge recorded only a 42 per cent conviction rate, she said.
Overall, studies have shown juries are three times more likely to convict in identical cases if DNA evidence is presented at a trial.
Courts should introduce short presentations to juries and not shy away from using multimedia which had been found to be effective in increasing the understanding of people with low DNA knowledge and among the younger generation, she said.
Another surprising finding of her study was the problems people had to assess their own learning. When testing the effectiveness of the presentations, researchers asked people to assess how much they had understood before testing them. Their self assessments did not match the objective assessments, she said.
This was a concern because much research about jurors was only based on their own assessment. ''If you just go to jurors afterwards and you ask 'how easy was it to follow the trial?', you can get the wrong idea about how well they are following it,'' she said.