Dickerson et al. (1992)
Testing Foot in the Door
Did a field experiment where they asked university students to conserve water in the dormitory showers. The researchers first asked a group of students to sign a poster supporting shorter showers to save water. Then they asked students to do a survey asking them to think about their own water usage. Finally the students’ shower time was monitored. Students who had signed the poster and had done the survey spent an average of 3.5 minutes less in the shower compared to the rest of the students in the dormitory.