Adherence to Personal Resolutions Across Time, Culture, and Goal Domains.

Goal setting is only somewhat more common than the failure to follow through on one's goals. Recognizing the challenge of long-term behavior change, we asked what best predicts long-term goal adherence: extrinsic motivation (the extent to which goal pursuit is experienced as a means to an end) or intrinsic motivation (the extent to which the same goal pursuit is experienced as an end in itself). In a year-long longitudinal study, U.S. adults set extrinsic New Year's resolutions, but intrinsic motivation predicted adherence to these goals more than extrinsic motivation (Study 1). These findings emerged among adults in China (Study 2) and when measuring goal adherence objectively using the number of steps U.S. adults walked over 2 weeks (Study 3). Understanding how intrinsic motivation affects long-term persistence critically informs interventions that promote goal pursuit. Indeed, increasing intrinsic (vs. extrinsic) motivation increased U.S. adults' goal adherence (Study 4). Overall, intrinsic motivation both predicted and causally increased goal adherence.