Social norms
社会规范
What are social norms?
Social norms are shared rules of conduct, sustained by other people’s approval and disapproval and by one’s own shame or guilt; breaking them draws social sanctions, from raised eyebrows to ostracism.[1] Social psychologists distinguish descriptive norms (what most people do) from injunctive norms (what most people approve or disapprove of).[2]
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Bars are real data (Cialdini, Reno & Kallgren, 1990, Study 1, 139 people).
Select a bar or a card for details.
Someone walks past · Comparison On a clean floor, after seeing a confederate simply walk past, 14% of people dropped the flyer from their windshield. Participants were hospital visitors returning to their cars; there were no bins nearby, so everyone who did not litter took the flyer into the car.
Someone drops a flyer · Lowest of the four On a clean floor, after watching a confederate drop a flyer, only 6% littered. The authors’ reading: the act drew attention to the fact that almost no one litters here. On its own, though, the gap from the comparison group (6% vs. 14%) was not significant; the authors suggest littering may already have been too rare to fall much further.
Someone walks past · Comparison With handbills, candy wrappers, cigarette butts and paper cups all over the floor, 32% littered after seeing someone simply walk past. Across all four groups, people littered far more on the littered floor (41%) than on the clean one (11%).
Someone drops a flyer · Highest of the four On a littered floor, after watching someone litter, 54% followed suit. The floor made far more difference when someone had just littered (54% vs. 6%) than when someone walked past (32% vs. 14%), a significant interaction, although 54% vs. 32% on its own was not significant. The authors argue that the act drew attention to the descriptive norm: everyone litters here.
Litter swept into piles · A cue to an injunctive norm In Study 4 the litter on the same garage floor was swept into three piles, a sign that someone disapproves of littering. After watching someone drop a flyer, 45% littered amid scattered litter but 18% beside the swept piles; with no one littering, the two were close (33% and 29%), a significant interaction. The authors conclude that what matters is which norm attention is drawn to, not that descriptive norms are inherently stronger than injunctive ones.
Energy use and the boomerang · Reporting the average can backfire In a field experiment, Schultz and colleagues (2007) told households how much energy their neighbors used on average. Households that had been using more than that then cut back, while those that had been using less used more: a boomerang effect. Adding a message of approval or disapproval, an injunctive norm, eliminated the boomerang effect.
Hotel towels · Replications disagree Goldstein and colleagues (2008) found in a US hotel that a card saying about 75% of guests reuse their towels worked better than a standard environmental appeal (44.1% vs. 35.1%). When Bohner and Schlüter (2014) repeated the study in two German hotels, reuse was high to begin with (roughly 70–90%); the “most people do it” message did no better than the environmental appeal, and in the second hotel it did worse (76.5% vs. 93.3%).
Social sanctions · From raised eyebrows to ostracism Elster argues that people often obey norms to avoid others’ disapproval, from raised eyebrows to ostracism. That is not the whole story: internalized norms are followed even when no one is watching, and because sanctioning costs the sanctioner something, there are further norms against failing to sanction, though these tend to run out of steam two or three steps from the original violation.
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Key points
- Elster set social norms apart from law: legal norms are enforced by specialists whose job it is, social norms by ordinary members of the community. Internalized norms are followed even unobserved.[1]
- In a parking-garage study, 41% of people dropped a windshield flyer on a littered floor, versus 11% on a clean one; after watching someone litter, the gap widened to 54% versus 6%.[2]
- Telling households their neighborhood’s average energy use cut consumption among high users but raised it among low users; adding a message of approval or disapproval removed this boomerang effect.[3]
- In a US hotel, a card saying most guests reuse their towels beat a standard environmental appeal; replications in two German hotels found no such advantage.[4]
An example
When Lin’s housing estate began sorting its trash, a notice in the stairwell said many residents were still sorting it wrong. Later the building management replaced it with “80% of households in this building sort correctly” and thanked careful households in the residents’ group chat. Lin started sorting carefully too.
Misreadings and limits
A common mistake is to fight a behavior by stressing how many people do it, which advertises it as the norm. Cialdini and colleagues warned that drawing attention to a littered setting tends to increase littering;[2] in the energy study, average-use feedback alone led low users to consume more.[3]
Sources
- 1 Elster, J. (1989). Social norms and economic theory. Journal of Economic Perspectives, 3(4), 99–117. doi:10.1257/jep.3.4.99
- 2 Cialdini, R. B., Reno, R. R., & Kallgren, C. A. (1990). A focus theory of normative conduct: Recycling the concept of norms to reduce littering in public places. Journal of Personality and Social Psychology, 58(6), 1015–1026. doi:10.1037/0022-3514.58.6.1015
- 3 Schultz, P. W., Nolan, J. M., Cialdini, R. B., Goldstein, N. J., & Griskevicius, V. (2007). The constructive, destructive, and reconstructive power of social norms. Psychological Science, 18(5), 429–434. doi:10.1111/j.1467-9280.2007.01917.x
- 4 Bohner, G., & Schlüter, L. E. (2014). A room with a viewpoint revisited: Descriptive norms and hotel guests’ towel reuse behavior. PLoS ONE, 9(8), e104086. doi:10.1371/journal.pone.0104086
Last checked against sources: October 28, 2026