Juries trying criminal cases are likely to be more lenient when the person in the dock is physically attractive, psychologists say.
Jurors could be influenced by attractiveness, the study says
Scientists gave a fictitious transcript of a mugging to 96 volunteers, along with a photograph of the defendant.
The York and Bath Spa universities team found the jurors were less likely to find attractive defendants guilty.
But ethnicity had no effect on whether the defendants were found guilty, the researchers added.
The study, which was presented to the British Psychological Society's annual conference, also allowed the jurors to decide the verdict.
Unattractive black defendants were given the harshest sentences, irrespective of the ethnicity of the "juror".
Lead researcher Dr Sandie Taylor said: "We set out to consider the influence of physical attractiveness and ethnicity of a defendant depicted in a photograph on mock jurors' decisions of verdict, extent of guilt and sentencing.
"Our findings confirm previous research on the effects of defendant characteristics, such as physical attractiveness, on the deliberations of jurors.
"Attractive defendants are, it seems, rated less harshly than 'homely' defendants, so perhaps justice isn't blind after all.
"It is interesting that being an unattractive black defendant only had an impact on sentencing and not on jurors' verdicts of guilt although of course in the real world jurors would not be making decisions about the sentence.
"I think, however, it is a positive finding that neither black nor white participants showed a bias towards their own ethnic group."
Her Majesty's Court Service, which is in charge of selecting jurors, refused to comment on the findings.