Disturbing study on drift toward the fallacy of the middle ground, even between people with uneven expertise. Who’s seen this play out in class? An instructor says one thing. A novice student says something contradictory. Other students seem to give their statements equal weight and think the truth is somewhere in between.

Example: an instructor is talking about the importance of preserving the scene of a self defense incident. A student chimes in with the almost-inevitable “just drag the body into the house” chestnut. Despite being the middle ground, dragging the body half-way into the house is not the right answer.

This can also play out in decision-making in curriculum development groups, instructor teams if the lead isn’t leading, or any decision-by-committee process.

From a write-up at the Washington Post, The science of protecting people’s feelings: why we pretend all opinions are equal:

…an important successor to the Dunning-Kruger paper has just been come out — and it, too, is pretty depressing (at least for those of us who believe that domain expertise is a thing to be respected and, indeed, treasured). This time around, psychologists have not uncovered an endless spiral of incompetence and the inability to perceive it. Rather, they’ve shown that people have an “equality bias” when it comes to competence or expertise, such that even when it’s very clear that one person in a group is more skilled, expert, or competent (and the other less), they are nonetheless inclined to seek out a middle ground in determining how correct different viewpoints are.

Yes, that’s right — we’re all right, nobody’s wrong, and nobody gets hurt feelings.

 

Abstract of the paper, Equality bias impairs collective decision-making across cultures:

We tend to think that everyone deserves an equal say in a debate. This seemingly innocuous assumption can be damaging when we make decisions together as part of a group. To make optimal decisions, group members should weight their differing opinions according to how competent they are relative to one another; whenever they differ in competence, an equal weighting is suboptimal. Here, we asked how people deal with individual differences in competence in the context of a collective perceptual decision-making task. We developed a metric for estimating how participants weight their partner’s opinion relative to their own and compared this weighting to an optimal benchmark. Replicated across three countries (Denmark, Iran, and China), we show that participants assigned nearly equal weights to each other’s opinions regardless of true differences in their competence—even when informed by explicit feedback about their competence gap or under monetary incentives to maximize collective accuracy. This equality bias, whereby people behave as if they are as good or as bad as their partner, is particularly costly for a group when a competence gap separates its members.

Download paper from PNAS (free, PDF): Equality bias impairs collective decision-making across cultures, Ali Mahmoodi et al