In all friend groups, we have those that make the plans, those who straight up say they cannot come, those who say they are coming and actually show up and then those that say they are coming but bail (usually last minute) So how do you get people in the last category to fulfil their commitments? Here is a personal example:
Since the beginning of term, one of my flat mates has been trying to arrange a night out where all 8 of us are present. For some reason or the other, one or two people would bail and she would go back to square one arranging another night when everyone was available. It started off with my flat mate approaching each of us individually at different times and getting verbal commitments – 4 out of 8 people stuck to their commitment. Since this proved to be ineffective she moved on to writing about a plan in our group chat on WhatsApp – 5 out of 8 people stuck to their commitment. Finally, she made a Facebook group inviting around 20 people and 8 out of 8 members of the flat stuck to their commitment. Why?
There’s a simple explanation. A commitment is either a private or a public decision to act. When done more privately, for example, my flat mate asking us one to one in person or over private text messages, an individual does not feel as obligated to fulfil that commitment because he/she does not feel any fear of being socially rejected or the threat of cognitive dissonance when breaking the commitment is less. (Knox & Inkster, 1968) However, as the plans were written and started becoming more public, the number of individuals who stuck to their commitment increased till a 100% of the people came through. The Facebook group idea involved 20 people and since individuals saw that 18 people were going, they were under more pressure to fulfil the commitment and the fear of missing out was higher.
Therefore, if you want people to commit, make the plan public or written. Also make sure that it will cause them more dissonance for them to break the commitment than to fulfil it.
Knox and Inkster (1968). Post decision dissonance at post time, Journal of Personality and Social Psychology, 8, 319-323