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Neuroscientists Reveal the “Dark Secret” of Smart Decision-Making

Agree to disagree and you will likely get at the right answer together.


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Photo from Reuters/David W Cerny.

If you’ve ever dealt with the headache of a family gathering or a group project, you might imagine that it would be nice to decide things unilaterally. Yet Uta and Chris Frith, two neuroscientists who have been married for a half century, beg to differ.

The Friths have been studying the science behind decision-making for as long as they have been married—that’s five decades—and their research has shown that two or more heads really are better than one when it comes to making a reasoned choice. Not only that, but groups that disagree and argue before reaching a conclusion are especially well equipped to make good decisions, the couple writes in Aeon on Nov. 21.

There are a few simple reasons our personal judgments are less effective than decisions made by couples or groups, according to the Friths. First, our perceptions—physical and cognitive—are unreliable, so the more people are involved in a decision, the more likely it is that they will reach a conclusion based on a debate over various sensations, challenging each others’ experiences of reality.

Second, each of us has a limited knowledge set. If two or more people are working together, there’s more knowledge and experience to pool for a thoughtful conclusion. And if the group is diverse, the decision is bound to be based on a wide range of experiences and information, making reaching a correct answer all the more likely. Also, because we all have unconscious biases, we need other people to compensate for these, pointing out deficiencies in our thinking.

Somewhat counterintuitively, the Friths contend that disagreement is the key to reaching sound conclusions.”[A]rgument often helps,” they write. “It’s the dark secret of good group decisions.”

The neuroscientists point to a study (pdf) from the University of Nebraska on collaborative reasoning that showed groups of psychology students always performed better when solving a logic puzzle than individuals did. Alone, people often got the answer wrong. Together, they came to the correct conclusion. The study notes that the groups’ superior performances were based on collaborative construction of structured arguments that were more sophisticated than the reasoning of individuals.

An analysis of the discussion among groups solving the logic puzzle showed that the study’s subjects often challenged each other to justify their answers and consider different approaches, ultimately resulting in a much higher likelihood of solving the problem correctly.

Resistance to others, which can seem unpleasant, actually has advantages. Our tendency to resist other people’s thinking improves group decision-making, the Friths argue.

Of course, the neuroscientists concede, sometimes groups can also make bad decisions. They attribute these errors to people harboring a hidden agenda. If one member of the group is advancing a particular argument while secretly working to promote an interest that’s not explicit, then whatever discussion the group gets into probably won’t touch on all the actual factors at play, and can lead to mistaken conclusions.

Also, communication problems can muddy decision-making. While a diverse group of people may see a problem from many angles, members may not agree on a common meaning for certain words, or share a common goal. In that sense, then, diversity can become a hindrance.

But when groups become too cohesive and start thinking alike, an even greater danger arises: groupthink, or a tendency to consider things similarly. The Friths point to their own 50-year union as evidence of this, writing:

The two of us argue far less than before. Rather than testing each other’s opinions, we reinforce them. With a few exceptions, we agree about what is good in art and science, and are cozily confident that we have good taste and good judgment. Psychoanalysis is nonsense. French songs are overrated. Brioche buns do not go with burgers.

To keep making well-reasoned decisions, the Friths—now comfortably accustomed to each other’s thinking and often in agreement—say they have to force themselves to not let conversation get too “cozy.” In other words, though they may want to agree, they make themselves challenge one another anyway.

So although it might superficially seem nice to never have to argue with your partner or disagree with your esteemed colleagues, it turns out that’s not quite right, and won’t help you reach smart and thoughtful conclusions. Instead, butt heads.

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This post originally appeared on Quartz and was published November 27, 2018. This article is republished here with permission.

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