In 2006, USA Today reported a study in which researchers selected a large number people who had made New Year’s resolutions. They then divided these people into two categories: those who had set New Year’s resolutions and written them down and those who had set New Year’s resolutions but had not written them down.
Twelve months later, they followed up on the respondents in this study, and what they found was astonishing. Of the people who had set New Year’s resolutions but had not written them down, only 4 percent had actually followed through on their resolutions. But among the group who had written down their New Year’s resolutions (an exercise requiring only a couple of minutes), 44 percent had followed through on them. This is a difference of more than 1,100 percent in success, and it was achieved by the simple act of crystallizing
Tracy, Brian (2010). No Excuses!: The Power of Self-Discipline (pp. 65-66). Vanguard Press. Kindle Edition.