Although justice is supposed to be "blind," a new study finds that attractiveness influences conviction and sentence length.

Cornell University researchers found that unattractive defendants are 22 percent more likely to be convicted, and tend to get hit with longer, harsher sentences – with an average of 22 months longer in prison recommended by the study's participants.

The study identified two kinds of potential jurors: Those who reason emotionally and give harsher verdicts to unattractive defendants, and those who reason rationally and focus less on defendants' looks.

One processes information based on facts, analysis and logic. The other reasons emotionally and may consider such legally irrelevant factors as a defendant's appearance, race, gender and class, and report that the less-attractive defendant appeared more like the "type of person" who would commit a crime.

"Our hypothesis going in was that jurors inclined to process information in a more emotional/intuitive manner would be more prone to make reasoning errors when rendering verdicts and recommending sentences. The results bore out our hypothesis on all measures," said lead researcher Justin Gunnell.

The study, "When Emotionality Trumps Reason," will be published in an upcoming issue of the peer-reviewed journal Behavioral Sciences and the Law.

Participants — 169 Cornell University psychology undergraduates – took an online survey to determine the degree to which they processed information rationally or emotionally. They were then given a case study with a photograph of an actual defendant and his or her general profile. They read real jury instructions and listened to the cases' closing arguments.

While both groups convicted attractive defendants at similar rates and were less biased in the face of strong evidence or very serious offences, the jurors' reasoning style tended to play out "in cases where the evidence is ambiguous and the charged offense is somewhat minor," Gunnell said.

Gunnell says the study could contribute to refinements in jury selection techniques. In cases where the evidence strongly favors one side, a lawyer might want to identify rational jurors. But in a case with an emotional tug, a defense attorney might try to screen out highly rational jurors.

"Every person is capable of reasoning via either system and likely uses each system to some degree depending on context," Gunnell said. "The degree to which one system predominates the other is a factor that varies, depending on the individual’s natural preference and style."

He said the findings are important because "22 months may not seem like a lot to an outsider, but I guarantee that to the person serving the sentence it will seem like a lot."

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