A lighthearted intervention using the ‘affect heuristic’ to evoke empathy for furry city-dwellers, successfully reduced gum litter in busy areas.
Gum litter remains a persistent issue—sticking to pavements, clinging to shoes, and proving notoriously difficult to clean. Its non-biodegradable composition, usually a blend of synthetic rubber and plastic-like polymers, takes 20–25 years to break down, leaving microplastics that pollute soil and waterways. Additionally, cleaning gum off streets requires intensive methods that consume water, energy, and often involve chemicals. This litter also negatively impacts wildlife, as animals may ingest gum or get it stuck on their paws or fur, leading to health issues and harm to urban and natural ecosystems.
In collaboration with Mars Wrigley and the gum industry, targeted interventions were developed to encourage proper disposal and reduce environmental impacts.
Many people believe gum littering is caused by a small group of antisocial individuals. However, ethnographic research by Behaviour Change showed that context, rather than character, often determines littering. Most people don’t drop gum habitually, but certain situations increase the likelihood of littering. Researchers identified six of these high-risk circumstances and designed behavioural interventions accordingly.
In one workshop, participants expressed concern about animals getting stuck in gum, leading to the development of the “cute kitten” intervention. Using the ‘affect heuristic,’ the design featured a kitten on signs and stickers placed strategically on bins and lampposts to leverage emotions and humour, effectively reminding people to dispose of gum properly.
The result: A 9-week evaluation measured gum littering rates before and after the intervention, using highly accurate gum counts adjusted for footfall using mobile phone data. The “kitten” signage reduced gum litter by up to 61%. When paired with a preliminary gum cleanse, the combination achieved an 80% reduction in gum littering.
Do you know of any other nudges that prevent gum littering? Feel free to get in touch: hello@green-nudges.com
From Tasha Richardson, Senior Behavioural Intervention Designer at Behaviour Change. Behaviour Change is a not-for-profit behavioural science consultancy, working with charities, businesses and government to design creative and innovative on-the-ground interventions to encourage pro-social and pro-environmental behaviours.
A European research project tested digital nudges for sustainable parcel delivery — gentle signals worked, pressure tactics backfired.