What The Psychology Of Jury Deliberation Means For Trial Outcomes

The Cosby trial jurors entered their fifth day of deliberations on Friday.
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Jurors on the Bill Cosby trial entered their fifth day of deliberations at the Montgomery County Courthouse in Pennsylvania on Friday, a day after telling Judge Steven O’Neill that they could not come to unanimous consensus on any of the drugging and sexual assault counts Cosby is accused of.

Although other celebrity trials have lasted longer, five days is considered to be a long deliberation period. And long deliberations can mean one of two things, according to experts: Either jurors are being thoughtful ― or there’s a battle over single truths going on.

“It can just polarize into two groups who are taking opposing views,” said Deanna Kuhn, a professor of psychology and education at Columbia University’s Teachers College who has published research on juror decision-making.

O’Neill rejected the defense’s motion for a mistrial and promised to give the jury as long as it needed to deliberate.

“You must agree unanimously,” he told them.

It’s notable that the Cosby trial jurors are sequestered ― living in a hotel away from family or loved ones ― which puts additional pressure on them to reach a verdict.

Being on a sequestered jury is “not unlike being in a medium-security prison,” Paula Hannaford-Agor, director of the Center for Juries Studies at the National Center for State Courts, told The New York Times.

One sign the jurors may be taking their time out of thoughtfulness and caution rather than discord: The jurors asked the court to define “reasonable doubt,” which is the standard of proof in a criminal trial.

A reasonable doubt, the judge explained, is a real doubt, one that would cause a juror to hesitate.

And in states such as Pennsylvania, where the trial is taking place, reasonable doubt “does not mean proof beyond all possible doubt or to a mathematical certainty,” according to the model jury instructions adopted by the U.S. Court of Appeals for the Third Circuit.

“That tells us that they’re concerned about this certainty issue,” Kuhn said of the jury’s question.

According to Kuhn, people often interpret reasonable doubt differently.

Some jurors are “storytellers” ― they construct a narrative of what happened and then see if evidence presented fits with their narrative. If evidence doesn’t fit with their narrative, they may ignore it. Such individuals tend to be more certain about their decisions, and in Kuhn’s experience, also hand down more extreme verdicts.

Other jurors are “scientists” ― they look at evidence on its own, examining it for quality and logic, but don’t seek a single true narrative of what happened. This leads to more complex, less certain deliberation and moderate verdicts.

Still, it’s important to note that jury pools don’t neatly fall into “certain” and “uncertain” camps. “It’s a continuum with a lot of middle ground,” Kuhn said.

When these two types of individuals exist on a single jury, either type can prevail.

In Kuhn’s research, scientist type jurors were more likely to influence the thinking of storyteller jurors in a one-on-one experiment, although that did not necessarily lead them to change their positions.

For now, however, it’s unclear what kind of thinkers are on the Cosby jury or how long their deadlock will last.

This reporting is brought to you by HuffPost’s health and science platform, The Scope. Like us on Facebook and Twitter and tell us your story: scopestories@huffingtonpost.com.

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