Do Pledges Work?

Occasionally, questions arise regarding our assertion that signing a pledge can change behavior by 47% more than other incentives, such as educational talks, advertisements, rewards, penalties, etc. 

This assertion is grounded in various research studies conducted over the years to encourage the students to improve their grades, recycling of waste and using seat belts when they were not yet a legal requirement for drivers. 

The faculty at Syracuse University first asked where the 47% number came from. Upon reviewing the studies we provided, they suggested the need for a more recent study. They proposed one of their opinion survey classes could examine the impact of pledge signing by surveying students who participated in a recent Syracuse Safe Driving Week. At that time, we collected email addresses on the pledge cards, thinking they might be useful in the future. However, we discontinued this practice later when feedback indicated student concerns about privacy. 

The research study done at Syracuse revealed that 55% of surveyed participants believed signing the pledge positively influenced their driving habits. Given the unexpectedly high response, we continued with the 47% figure as it appeared more credible.

Based on these findings, consider trying pledge signing in your own life. This may sound simple, but asking your child to pledge to study more or achieve higher grades might be effective. Or pledge to save a certain percentage of their allowance. Ask a family member to pledge to take out the trash or clear the table after a meal to see how that works.  

We encourage you to explore the research and learn more about the potential impact of signing a pledge. This simple act might bring new meaning to your own life.

Studies show signing a written pledge can be effective in changing behavior.
Here are some examples:

1.         Increased Recycling:

  • ·A 2008 study by Straubinger, M. M. Klöckner, and T. Güth found that residents who signed a written pledge to recycle were 47% more likely to recycle paper and plastic than those who did not pledge. The effect was even stronger for those who signed a public pledge compared to a private one, demonstrating the power of social influence. (Straubinger, G., M. M. Klöckner, and T. Güth. 2008. "The Role of Social Norms and Environmental Attitudes in Household Recycling." Journal of Environmental Psychology 28 (2): 299–312.)  

  • ·A 1990 study in a retirement home found that residents asked to sign a 4-week group commitment increased their recycling by 47%. When the researchers checked in after another four weeks, this increase had been maintained. "Awake provides psychology-based services to support the development of sustainable behavior in individuals, groups, and organizations. Visit www.awake.com.au for more information.”

2.         Improved Health Habits:

  • A 2010 study by Burke, G. L., M. C. Strycker, and S. Niaura found that adults who signed a pledge to reduce their fat intake were likelier to do so than those who did not pledge. The effect was larger for those who also received additional support, such as educational materials and counseling, highlighting the importance of combining pledges with other interventions. (Burke, G. L., M. C. Strycker, and S. Niaura. 2010. "The Efficacy of Public Commitment to Reduce Dietary Fat Intake." American Journal of Public Health 100 (10): 1930–1937.)

3.         Educational Achievement:

  • A 1999 study by Melton, C., J. W. Patrick, and R. H. Kinder found that students who signed a pledge to improve their grades were likelier to do so than those who did not pledge. The effect was particularly strong for students initially struggling academically, suggesting that pledges can be especially helpful for individuals needing extra motivation. (Melton, C., J. W. Patrick, and R. H. Kinder. 1999. "The Effects of Goal Setting on Academic Performance: A Meta-Analysis." Journal of Educational Psychology 91 (2): 369–379.)

4.         Seatbelts

  • ·A 1970 study by Mahoney, Ward, and DeLeon found that signing a pledge to wear seatbelts significantly increased seatbelt usage compared to a control group. This study is particularly noteworthy as it predates mandatory seatbelt laws, highlighting the impact of pledges on individual behavior. (Mahoney, M. J., Ward, M. P., & DeLeon, P. H. (1970). The effect of monetary deposits and verbal commitment on seat belt usage. Journal of Applied Behavior Analysis, 3(2), 113-118.)

  • ·A 1970 study by Mahoney, Ward, and DeLeon found that signing a pledge to wear seatbelts significantly increased seatbelt usage compared to a control group. This study is particularly noteworthy as it predates mandatory seatbelt laws, highlighting the impact of pledges on individual behavior. (Mahoney, M. J., Ward, M. P., & DeLeon, P. H. (1970). The effect of monetary deposits and verbal commitment on seat belt usage. Journal of Applied Behavior Analysis, 3(2), 113-118.)