How to Convince People to Save Water, Using Psychology

Water irrigation pipes on a farm in Southern California. (Photo: Eddie J. Rodriquez/Shutterstock)

Shame them and pressure them, and maybe make them pay some money.

After four years of drought, California governor Jerry Brown announced this week that the state is imposing a mandatory 25 percent cut in water use for the vast majority of the state's water districts. This is the first time in California history officials have mandated people use less water.

As Californians prepare for the cut, we thought we would take a look at some of the strategies studies have found work to convince people to use less water. Overall, it seems discomfort, peer pressure, and shame are the best water-saving tools. Our evidence:

1. EVERYBODY ELSE IS DOING IT

Do you heed those hotel-room placards that urge customers to re-use their towels? You might, if you knew others did. One recent study compared the effectiveness of different wording on those signs. Signs that read, "75% of guests in this room usually use their towels more than once" worked best. A previous studyalso found something similar. It seems people respond most to social norms, and the more specific the population ("guests in this room"), the better.

2. SHOWER SHAME

Here's a study in which silent, naked peer pressure made all the difference. As writer Rick Paulas wrote for Pacific Standard last year:

In his book Fostering Sustainable Behavior, psychologist Doug McKenzie-Mohr describes a study about trying to get college students to conserve water while using a gym shower. If a sign was posted in the shower urging students to turn it off when they weren't using it, only six percent followed the instruction. But when a researcher was planted in the shower and silently performed the conservative act, a whopping 49 percent of students followed along. If two researchers were planted, that number rose to 67 percent of students.

3. DOUBLE DISCOMFORT

In a wonderful study, published in 1992, researchers forced study participants to be hypocrites. They made participants tell other people to take shorter showers. Then they reminded participants that they had not taken short showers in the past. Study volunteers subjected to this combination of conditions took significantly shorter showers than participants who only talked to others about showering, or were reminded of their past poor behavior.

Of course, California's new restrictions will empower the state to deploy something even more straightforward than social norms and shame. Should water districts not meet their goals, officials are prepared to levy fines, the New York Times reports. Some previous research has found pricing and fines are effective in getting people to save water in certain situations.

It looks like water-saving always requires a little pain, whether it's to your pride, or to your wallet.