Upward Trends: A Lever for Increasing Rare Behaviors

Why do people recycle, save energy, conserve water, and believe in climate change? One reason is that people follow those behaviors they perceive to be common – “descriptive norms.” Presenting a behavior as common, then, influences people to conform to that behavior. For example, O-Power, a company that helps utility companies design home energy reports, provides customers with feedback about energy use relative to their neighbors’ energy use. When customers see that they are using more energy than those around them, they reduce their energy consumptions significantly. Using this descriptive norm tactic has helped save over 664 million kilowatts of energy. However, other behaviors can’t be increased via a descriptive norm message because only a minority of people engages in the behavior. How can we harness the power of descriptive norms for behaviors that are in fact uncommon? One strategy may be to present information that a particular behavior, while still uncommon, is on an upward trend. For example, perhaps in 1990, 5% of an area’s residents had weatherized their homes (or recycled, or taken the bus); in 1995, 10% had done so; in 2000, 15% had done so, etc. People might perceive this upward trend as an indication that in the future, a behavior will be common, thus influencing them to adopt the behavior now. We designed an experiment to test this hypothesis, comparing the effects of an upward trend on behavior compared to other plausible, but possibly less effective or counterproductive, tactics (saying a large number of people behave this way, giving a lamenting plea, etc.). The results may suggest that upward trends are an effective way to honestly promote behaviors that are sustainable, but that haven’t yet become commonplace.