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I, the Jury, Could Be Biased

Tendency to make facts fit sways decisions, study says

MONDAY, July 2, 2001 (HealthDayNews) -- If you wind up on a jury, any leanings you have about who might win the case could make you distort the facts to fit, a new study says.

"Once you develop a leaning or a tentative preference based upon some case-specific information, that tentative leaning influences how you distort the information," says Kurt A. Carlson, a doctoral candidate at the Johnson Graduate School of Management at Cornell University and lead author.

The process, known as predecisional distortion, says Carlson, could unknowingly make jurors more likely to make a mistake, and the premise raises questions about whether the judge's usual instructions to the jury not to reach a premature verdict are enough.

Researchers did two experiments to test whether predecisional distortion would be present in a courtroom.

In the first, college students were presented subjects in a mock civil and criminal case. They received packets of detailed information including case facts, opening arguments and witness affidavits, and they viewed a real video shown to actual prospective jurors in Wisconsin, instructing them to not reach "hasty opinions or conclusions."

As the students plowed through the information, they marked whether each piece of evidence favored the plaintiff or defendant, and indicated what their verdict would be at each point. At the conclusion, they were to reach a verdict without referring back to their notes.

In a second experiment, the same method was tested on 148 prospective jurors drawn from a jury pool in the county courthouse.

In both experiments, predecisional distortion greatly influenced the outcome, with three-quarters of the students exhibiting distortion to favor their leading verdict.

Among the jury pool, which had more adults, the numbers were even higher -- 85 percent gave into their leanings. And the more confident the juror was with his verdict at any given time, the greater the distortion, say researchers.

"No one is crystal clear what the mechanism is," says Carlson. Initial leanings are very natural. "The bigger question is, what is the mechanism driving the distortion of new evidence?"

"We believe it is a coherence mechanism, trying to make sense of the words, to make sense of the casethat all the information should hang together to make some coherent story." If you're leaning toward one party in the case, you'll favor the evidence in support of your side, he says.

"There's no question that jurors distort facts," says Howard L. Nations, a Houston-based lawyer who writes and speaks extensively on juror bias. "Jurors form a story about what the trial is about, and by the end of the opening arguments and first witness," they've formed their story.

Then, Nations says, "they test the new data they receive against their own model of the case and will adopt the information to conform to what they believe. They tend to see what they want to see and hear what they believe."

In the absence of compelling new data, Nations adds, the jurors are "left with nothing but their predispositions to put into the model," and they will tend to stay with the story they developed early on in the trial.

That's why a good trial attorney presents his most compelling evidence at the beginning of the trial, Nations adds. "If you're bringing in valuable evidence late in the game after the [juror] model is formed, it won't be received as credibly."

That real prospective jurors showed a higher level of distortion than students does not surprise either the researchers or Nations.

Student lack the life experiences of the older jurors, Carlson says, and perhaps they are more analytical, which reduces the tendency to distort.

Nations adds that during deliberations, jurors often base their feelings and leanings based on their personal life experiences. "Jurors will use their predispositions to fill in the gaps in the evidence," he says, calling on "I know it's true because it happened to me."

Gen-X'ers, says Nations, "believe because they choose to believe," rather than having the experience to back it up.

Dealing with such predecisional distortion in the courtroom is a challenge, says Carlson. One of the biggest problems is that people may not be aware of their bias or that they are distorting the facts.

"Maybe it would help to explain to jurors how even a tentative leaning can influence how new evidence is perceived," Carlson says. "Our view is that any form of overall judgment should be delayed as long as possible."

But Nations has doubts that predispositions can ever be eliminated. "By the end of the first witness, jurors have formed their own model about what the case is all about," and a judge's instruction is not likely to change that.

The study appears in the June issue of the Journal of Experimental Psychology: Applied.

What To Do

Learn more about the legal system on The Juror's Web site.

Read other articles on juror attitudes and perceptions on

SOURCES: Interviews with Kurt A. Carlson, Johnson Graduate School of Management, Cornell University and lead author; Howard L. Nations, lawyer, Houston, Texas, board certified in personal injury and civil trial law; June 2001 issue of the Journal of Experimental Psychology: Applied
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