Promises in Lasting Relationships

In this blog, I am going to make and keep two promises.  One promise is to identify one sure-fire way to know you are watching a bad movie. The second promise is to discuss the disconnect that research has discovered between making promises and keeping promises in relationships. (I also just happen to promise that these two things will tie together in the end!)

There are plenty of bad movies out there, and when I am in a theatre watching a movie that starts to plunge down into the pit of despair, most of my energy is directed toward the struggle to decide if I should leave in the middle. Fortunately, there is one movie line that allows me to just get up and go:  C’mon man! Your brain is writing checks your body can’t cash!  At that moment, all becomes clear, the stars align, the universe is in one and an aisle-way out of the theatre runs through it.  (I often think that in a few years characters will have to say something like: C’mon man! Your mind is using a debit card your body can’t afford.  That would be more entertaining than the original.) So, promise one fulfilled—if this one humdinger of an overused piece of dialogue pops up, you are definitely in a bad movie.

On to promise two! A recent study by Johanna Peetz and Lara Kammrath, psychologists at Laurier University in Waterloo, Canada looked into how couples in happy relationships make and break promises.  First, research has made clear that keeping promises has many positive consequences, including fostering trust and indicating to one person that their partner is responsive to their needs.  And, of course, we know that breaking promises has many negative consequences. Peetz and Kammrath asked couples to participate in a study in which one partner was asked to talk about something they do that annoys the other.  After this conversation they were given the chance to make a few promises for changes in their behavior that would address the conflict they discussed. The couples returned to the lab 14 days later so the experimenters could find out how many promises were kept.

As you might expect individuals who felt more positively toward their partner and who were more concerned with their partner’s needs (what Peetz and Kammrath termed responsiveness motivation) made more promises. That is, those who were happier with the relationship and who were more motivated to be responsive to their partners wanted to do more to resolve the conflict that was being created by their behavior. That’s good.  But being concerned with their partner’s needs did not mean that they kept all of the promises.  After 14 days researchers learned that about 73% of the promises that were made were kept.  More than one out of every four promises was broken!

Now, take a moment and think of how it feels when your partner does not follow through on a promise.  Terrible, right? We may well decide that they must not care about us if they are willing to break their promise.  But this is not what Peetz and Kammrath found. They found no relationship between responsiveness motivation and promise keeping.  Those who were very concerned with their partner’s needs were just as likely to break promises as those who reported being less concerned with their partner’s needs.  Participants in the study weren’t breaking promises because they didn’t care what their partner felt.  Rather, they were breaking some promises because they weren’t able to keep all of them—they encountered obstacles, became distracted, weren’t good at achieving goals, perhaps in part because they tended to be lower in conscientiousness.  Individuals who are not good at meeting goals they set are similarly not good at keeping promises they make.

To tie it all together (promise number three!), let’s focus on what happened.  Individuals were over-promising and under-keeping.  Their desire to show their partners they cared caused them to make promises they weren’t able to keep.  Get it—their brains were writing checks (making promises) their bodies couldn’t cash (keep).  Fortunately for couples, if this bit of cliché pops up in your relationship, you don’t have to walk out! As the study shows, we all make promises with the best of intentions, and we all fail at keeping them.   When it comes to making and keeping promises, it may be a good idea to follow the well-known business principle to “under promise and over deliver.”

In case you are interested…

Peetz, J., & Kammrath, L. (2011, January 17). Only because I love you: Why people make and why they break promises in romantic relationships. Journal of Personality and Social Psychology. Advance online publication.
doi: 10.1037/a0021857.

About Alan Strathman

Alan has spent 24 years as a professor of psychology at the University of Missouri. He is the founder of and contributes content regularly through blog posts and e-books that communicates the findings of psychological research on relationships. If you would like more information about Alan, please visit