A few weeks ago a friend approached me and said that he'd like me to keep my Thursday 2 weeks from then free for his birthday party, in response I just off-hand agreed and we moved on in the conversation with the understanding that I would be present at his party. What I didn't know however was that I was going to fall incredibly ill with a high fever a few days before the party itself. Nevertheless I still remained firmly confident that I would be going despite throwing up just a day before the event itself. Any thoughts I had of not going were instantly dismissed as - through reflecting upon my feelings at the time - I can see that the prospect of not going elicited feelings of shame, reminders of previous times where I have had to bail out on something I said I would do (and subsequently feeling bad because of it) and also just the possibility that people would mention my absence and be annoyed by it (I don't want people, especially friends, to be annoyed at me).
The question is, why was the prospect of not going such big issue? I had a perfectly valid reason, I've had to pass up such occasions before and haven't always been negatively affected by it and my friend isn't so vindictive to think I'm coming up with excuses because I can't be bothered. Through my research for this post, I found that the answer is actually a well-documented and relatively simple phenomena, known as the 'Commitment Trap'.
Wang and Katzev (2006) looked specifically at this phenomena to see just how much it had an effect on people who were caught up in it. In their study which took place over 11 weeks with 3 distinct phases the researchers were looking at how a public verbal commitment to increase 'recycling behaviour' would impact upon the individuals' said behaviour. Recycling was chosen because in comparison to other behaviours it is relatively easy to measure to gain an objective result (i.e. just by measuring the amount of paper in the recycling box).
The initial phase of the experiment was the control, with the researchers looking at how much recycling behaviour the subjects did without any manipulation. This took 3 weeks and was followed by the second phase, whereby the researchers actively approached the subjects, discussed and explained the various merits of recycling and crucially asked the subjects to sign a 'pledge' to commit to the "recycling project" that the experimenters had outlined for 4 weeks. The final phase after this tracked the participants recycling behaviour after the agreed terms of the pledge had been fulfilled.
The graph above marks each phase and plots just how much was recycled on each measuring day and the average amount recycled over the course of the phase. It can be seen that during the second 'commitment phase' the participants recycled approximately 4lb's more of paper on average than they did before committing to the pledge, an increase of almost 50% in their recycling behaviour.
So just by committing someone to do something beforehand, you greatly increase the chances of them doing that. To my personal example, I ended up not going and felt terrible because of it even though my friend completely understood, I only messaged him an hour before the arranged start that I wasn't going because I really didn't want to have to type it out as it would finally confirm that I am jumping on this commitment.
Obviously my friend didn't consciously trap me to a commitment, he just wanted to remind me of something but if he hadn't had brought it up when he did - a couple weeks before the event - and where he did - in a public place with others around - I am sure I wouldn't have felt so motivated to go and when it was clear that I couldn't so frustrated and annoyed that that was the case. The commitment trap can therefore be seen at least through this personal anecdote to be a particularly powerful means of getting something to do what you want.
Wang, T. H. & Katzev, R. D. (1990). Group commitment and resource conservation: two field experiments on promoting recycling. Journal of Applied Social Psychology, 20, 265–275.