by Ali Shiravand
Gregg Sparkman & Gregory M Walton. Psychological Science 2017
Telling someone that “Lots of people do X” sometimes persuades them to do the same. This paper shows that saying “More and more people are doing X” is an even stronger persuader even when doing X is against the popular culture of a society.
“Lots of people do X” describes a static norm. “More and more people are doing X” is a dynamic norm: it describes about how other people’s behavior is changing over time. Here we read that people are more likely to change their behavior if we persuade them with dynamic (vs static) norms.
Key finding is in Experiment 4 which is a field experiment conducted in a café on Stanford campus. People waiting in line at the café were invited by a sign to complete a survey on “costumer preferences” in exchange for 5$ discount. In the survey, key sentences were implanted to prime the subjects by a dynamic or static norm or a control (neutral) (see figure 1-2 below).
They then secretly tracked the subject’s food order to see if they order food with or without meat. The prediction was that those subjects who received priming by dynamic norm (figure 2) were more likely to order food without meat. The results (Figure 3), confirmed this prediction.
This is a very cool paper for a number of reasons: (1) they offer a very clever method for behaviour change; (2) they test their hypothesis in self-reports in the lab as well as measuring actual behaviour change in the real world outside of the lab; (3) they employ a very brave experimental design involving secretly tracking people’s food orders. Their design is a good example of how to do an ethically difficult experiment.
There is 4 other experiments in the paper. We hope this summary persuades you to read the paper completely.
Ali Shiravand is a student at the University of Tehran where he is doing an MSc in Artificial Intelligence. He also works as a research assistant at the UT Cognitive Systems Lab.