Make sure your audience understands that a “positive” feedback loop is not necessarily desirable

Abstract:

Your audience can’t understand climate change if they don’t understand feedback loops. Climate sensitivity to greenhouse gases is driven by multiple feedback loops, involving ice albedo, permafrost, clouds, wildfires, and more.

Feedback loops are challenging to teach and learn. Our research suggests that the terminology used to refer to these phenomena can be part of the problem. In everyday English, “positive” conveys “desirable” and “negative” conveys “undesirable.” But in Earth Systems, a “positive” feedback loop is one that amplifies an initial impetus, whereas a “negative” feedback loop is one that dampens it. To avoid the confound between causal structure and affect, some instructors say “reinforcing” and “balancing” instead of “positive” and “negative.”

Our study used a suite of 40 short narratives as stimuli. Each narrative had four variants: two with desirable outcomes and two with undesirable outcomes, crossed by two with a positive feedback loop causal structure and two with a linear causal chain structure. Among 160 undergraduates from the Temple University psychology participant pool, half were briefly instructed about “positive feedback loops,” while the other half received identical instruction about “reinforcing feedback loops.” The assessment task was to read each narrative and indicate yes/no, this is or is not a positive/reinforcing feedback loop.

A signal detection analysis approach allowed us to quantify two independent metrics for each participant: Bias (c) captures overall tendency to say yes it is a loop, while Sensitivity (d’) captures skill at distinguishing between loops and non-loops. We found that the participants as a group have a bias towards perceiving loops when narratives have desirable outcomes, but no such bias when narratives have undesirable outcomes. This bias exists regardless of terminology used. The “reinforcing” group had slightly less yes-it’s-a-loop bias than the “positive” group, and slightly better sensitivity in distinguishing loops from non-loops, but the alternative terminology did not eliminate the problem.

If your audience hears “positive” and thinks “desirable” when you talk to them about climate change feedback loops, it is possible that they will come away with an inappropriately rosy view of our planet’s future.