By Dr. Ken Broda-Bahm:
How good are you at knowing when people are telling you the truth and when they're lying? Generally, I'd wager that the average person probably thinks they're better than average. And those who are self-styled experts or who have undergone training in lie detection likely believe that they have a decided advantage in spotting the liars. There's just one problem with that: A long line of experimental research shows that when trying to detect falsehoods, even trained experts typically fare little better than chance. When tested in blind experiments, 'human lie detectors' are about as good as coin flips. A recent study (Klein & Epley, 2015) however, takes a different approach. Instead of simply testing individuals with and without training on their ability to detect deception, they looked at groups, specifically in regard to the question of whether deliberation improves their ability to tell truth from fiction.
The result? Groups indeed did significantly better than individuals at detecting deception. And it isn't just the benefits of aggregating individual opinions, the so-called "wisdom of the crowd," and it isn't due to the group's ability to spot and rely on the most capable lie-spotter in their group. Instead, the group's advantage in spotting lies has to do with the process of group discussion and the benefits of deliberation. I've written previously on the importance of understanding and adapting to the jury's process during deliberations. This research, however, adds to the pool of evidence showing the benefits of group discussion and, more specifically, the benefits of the jury model. This post takes a quick look at the research as well as a few implications that stem from it.