Research profile | The greening of a city


When it comes to encouraging people to engage with something, do positive messages work better than negative ones?

Katherine White

Opinion is divided, which is why Associate Professor Katherine White devised a test aimed at residents in Calgary to see which type of message worked best at persuading them to take part in a new curbside-recycling program.

While many local residents were excited to have access to a recycling initiative, some neighborhoods didn't appear to be embracing the program. 

In an effort to address this lack of engagement, White worked with the city to undertake a study to analyze various methods of encouraging people to recycle. 

She began the project by taking an initial measurement of people’s recycling behaviours. Working with a team of students, she measured the type and variety of garbage people were leaving on the curb. Once she had this baseline information, she divided the non-compliant areas into five groups and used a process called message framing to assess why some people might not be interested in recycling.

Message framing involves the presentation of information that is delivered in either positive or negative language.

In this particular case White wanted to determine what kind of message might be best to encourage recycling behaviours, as current literature related to conservation and messaging was mixed. Some researchers argue that positive messages are more effective when trying to encourage specific desired behaviours while others suggest that negative messages are more effective.

White and her colleagues wanted to find out which message type worked best with the groups in Calgary who seemed averse to recycling. “I started with an initial hypothesis,” notes White. “I believed that negative or positive behaviours were impacted by how people think about the message they receive."

In order to test her hypothesis she created four types of messages. Using recyclable paper doorknob hangers to convey information to residents, information was provided on both sides of the hangers. On one side she framed her note using positive language (if you recycle we will gain "y" number of trees) or negative (if you don’t recycle we will lose "x" number of trees). On the flip side there was information about the impact of recycling in concrete terms, such as "how to recycle," or abstract terms, such as "why recycle?"

The results showed that a positive message combined with abstract thinking was equally as effective as a negative message matched with concrete thinking. These two combinations resulted in an increase in Calgary’s recycling participation rates, adherence to recycling rules, and an increase in the type of recycling residents engaged in. 

What made this discovery even more exciting was the fact that a follow up study six months after completion of the project indicated that even without additional recycling messages, behavioural changes remained.

This shows that White’s research can have a significant effect on recycling programs across the country and ultimately our environment. 

Learn more about Associate Professor Katherine White and her latest research.