Character  &  Context

The Science of Who We Are and How We Relate
Editors: Mark Leary, Shira Gabriel, Brett Pelham
Jun 25, 2019

Following the Growing Crowd Toward Environmental Sustainability

by Chad Mortensen
World Global Ecology International Meeting

People tend to follow what most other people are doing, for better or for worse. On one hand, people’s tendency to follow social norms has been used to encourage environmentally responsible behaviors. For example, people use less energy in their homes when they find out that other residents in their area typically use less than they do, and people reuse their towels in hotels more if they find out most guests are reusing theirs.

On the other hand, social norms can also undermine attempts to change behaviors for the better. When a harmful behavior is common, people who are trying to reduce that behavior often mention how regrettably frequent  the undesired behavior is.  For example, in trying to get others not to litter, an environmental advocate may lament that many people are littering and that it’s a problem.  Unfortunately, this strategy is not just ineffective; it can actually backfire and encourage people to misbehave. Paradoxically, stressing that littering is common can induce people to litter because people tend to do what most other people do.

So, even though communicating information about social norms is very effective in increasing behaviors that are already popular, using social norms to change behavior is more difficult when most people are not performing the “good” behavior. Recently, however, my colleagues and I conducted research that reveals a solution to this problem, one that allows even a minority of people to encourage environmentally friendly behaviors… as long as that minority is growing.

We conducted two experiments to see if reading about behaviors that are performed by only a minority of people but that are trending upwards in popularity will encourage others to join in.  The first experiment tested whether a trending norm can reduce the amount of water people use while brushing their teeth.  In this study, some participants read that 47% of the students at their university were conserving water. Other participants read the same message but also read that this percentage was only 36% a year earlier, showing that conserving water is a growing trend.

The participants then went to another room for what they believed was a separate study about the taste of toothpastes. They chose a type of toothpaste from a number of options and brushed their teeth with it while the experimenter left the room. What they didn’t know was that a water meter hidden below the sink measured their water usage. We found that while people who read only that 47% of people were conserving water used 0.49 gallons of water, those who also read that this was up from 36% a year ago  used only 0.34 gallons.

In a second experiment, participants were asked to donate their time to help an environmental protection organization. However, before being asked for this favor, some participants read that it was not common to donate money to this organization, some participants read that it was not common to donate money to the organization but that donation rates were trending upward, and some participants got neither message.

As with the water conservation study, people were more likely to volunteer their time -- and to donate more time -- if they read that donation rates were increasing than if they read only about the norm.  Specifically, about 47% of the participants donated their time when reading about the upward trending norm compared to about 37% who donated  their time after reading about the norm alone.

Why are people affected by whether the proportion of people performing a behavior is increasing?  Digging deeper into our data, we found that people assume that trends will continue into the future.  So, when they read about an upward trend, they assume the behavior will become increasingly popular. This assumption leads them to be more likely to conform to the behavior. We conducted several other experiments looking into these effects and overall found our effects to replicate across studies. 

At the same time that we were conducting our research, Gregg Sparkman and  Gregory Walton, two researchers at Stanford University, were also studying  the effects of norms alone (what they called “static norms”) versus trends alone (“dynamic norms”) on other environmentally responsible behaviors and found effects similar to ours. They also found that trending norms affect behavior change by making people believe that change is more possible, that it’s more important to others, and that it’s more compatible with who they are.

In summary, although social norms are powerful tools to create social change, they can backfire if most people are performing a “bad” behavior. However, people are more likely to conform to the behavior of a small group if the group is growing, and that effect can be used to promote environmentally sustainable behaviors that aren’t yet common. 


For Further Reading:

Cialdini, R. B., Demaine, L. J., Sagarin, B. J., Barrett, D. W., Rhoads, K., & Winter, P. L. (2006). Managing social norms for persuasive impact. Social Influence, 1, 3–15. doi:10.1080/15534510500181459

Goldstein, N. J., Cialdini, R. B., & Griskevicius, V. (2008). A room with a viewpoint: Using normative appeals to motivate environmental conservation in a hotel setting. Journal of Consumer Research, 35, 472–482. doi:10.1037/e633912013-996

Mortensen, C. R., Neel, R., Cialdini, R. B., Jaeger, C. M., Jacobson, R. P., & Ringel, M. M. (2019). Trending Norms: A lever for encouraging behaviors performed by the minority. Social Psychological and Personality Science, 10, 201-210. doi:10.1177/1948550617734615

Sparkman, G., & Walton, G. M. (2017). Dynamic norms promote sustainable behavior, even if it is counternormative. Psychological Science, 28, 1663–1674. doi:10.1177/0956797617719950


About the Author

Chad Mortensen is an Associate Professor at Metropolitan State University of Denver. He conducts research on social norms, social influence, and self-control depletion.

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Why is this blog called Character & Context?

Everything that people think, feel, and do is affected by some combination of their personal characteristics and features of the social context they are in at the time. Character & Context explores the latest insights about human behavior from research in personality and social psychology, the scientific field that studies the causes of everyday behaviors.  

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