AAAS Diary: The Power of Peer Pressure

Reporter Graeme Stemp-Morlock blogs from the annual meeting of the American Association for the Advancement of Science (AAAS) in San Francisco.

Staying at the Parc 55 hotel in downtown San Francisco, I have used the same towel for my entire stay.  Why?

That was exactly the question that one of the best talks at the AAAS addressed.  Robert Cialdini from Arizona State University gave me an answer (and a BIG BIG BIG take-home message for environmental advocates) at the “Perception, Persuasion, and Climate Change:  Can Science Induce Urgent Action?”

Cialdini, a social scientist, used the tiny paper hanging door signs to see if he could encourage people to recycle towels at hotels.  Would cute animals and the environment motivate people? NO.

What about when the hotel promises to give some money to an environmental group in return for you recycling your towel?  Still, NO.

However, if the hotel gives money to an environmental charity first, then asks guests to help out there is an increase in towel recycling.  “People feel obligated to take an action if it is in return for a gift, favor, or service,” said Cialdini.  “It’s that notion of social obligation that we all live by.  When we receive we are obligated to give in return, and woe to those who don’t because we are trained from childhood you must not take without giving in return.”

But, the best motivator was not the environment or monetary incentives, but other people.  When Cialdini wrote on that tiny paper sign that most guests staying at the hotel recycle their towels, the number of people recycling towels doubled. 

According to Cialdini that’s the principle of consensus at work, which states that people want to follow many people and follow similar people.  Improving on the principle was when he wrote that most people who had stayed in that very room recycled their towels, and the results were incredibly high.

What this kind of social science means for the environmental movement is easy.  If you focus on economic or environmental reasons, you’re getting it wrong.  Focus on people, social norms, and local relationships and it really is easy to not only be green but to get others to be green.

-Graeme Stemp-Morlock


I have always recycled. I am staying in a hotel and used to always use my towels three or four days. But when I heard how Al Gore tells me to conserve while he used energy by the barrel, I figured why bother with these hypocrites leading the environmental movement.