Leveraging social norms for sustainable behaviour: How the exposure to static-and-dynamic-norms encourages sufficiency and consumption reduction of fashion

Contemporary communication platforms, ranging from social media to traditional news outlets, frequently present static norms, reflecting established behaviours (e.g., eating meat, drinking alcohol at parties) in combination with dynamic norms that signal evolving societal trends (e.g., adopting more plant-based diets, attending alcohol-free events). Despite the widespread exposure to such combined static-and-dynamic-norm communications, its influence on consumer behaviour remains unexplored. This research addresses this gap by conducting two laboratory experiments to investigate the impact of static-and-dynamic-norm communications on sustainable behaviour towards reduction of fast fashion consumption. The results demonstrate that participants exposed to the combination of unsustainable static and unsustainable dynamic norms purchased significantly fewer fashion items than those in other experimental conditions. This behavioural change is affected by a process of social moral cleansing , wherein participants, upon confronting with the widespread unsustainable behaviour of others, experienced a highlighted motivation to counteract these behaviours by acting more sustainably themselves. These findings contribute to the growing literature on social normative influence in sustainable consumption contexts. By identifying a novel and effective normative communication strategy for reducing consumption, this research offers valuable insights for researchers, designers and policy makers seeking to promote sufficiency-oriented behaviour and foster long-term sustainable behavioural change. • A social norm intervention combining an unsustainable static norm with an unsustainable dynamic norm is effective in reducing consumption in fashion. • Respondents chose a lower number of fashion items when exposed to the combination of an unsustainable static and unsustainable dynamic norm than to the combination of an unsustainable static and sustainable dynamic norm. • This is affected by a process of social moral cleansing, where consumers counteract the bad behaviour of others. • Static and dynamic norm communications can promote policy support for consumption reduction and sufficiency behaviour.