Adherence to Personal Resolutions Across Time, Culture, and Goal Domains.
Level 2 - randomized trial
Multi-study series incorporating longitudinal observational cohorts and an experimental intervention trial.
PubMed 40663621 · doi:10.1177/09567976251350960
What was done
Across four studies, researchers tested whether intrinsic motivation (experiencing pursuit as an end in itself) or extrinsic motivation (pursuit as a means to an end) best predicts goal adherence. They examined U.S. adults over a 1-year longitudinal New Year's resolution study (Study 1), replicated the findings in Chinese adults (Study 2), tracked 2-week objective step counts in U.S. adults (Study 3), and experimentally manipulated intrinsic versus extrinsic motivation to assess causal effects on goal adherence in U.S. adults (Study 4).
What was found
The abstract reports no numeric values, effect sizes, or confidence intervals. It qualitatively reports that intrinsic motivation predicted resolution adherence better than extrinsic motivation in both U.S. and Chinese samples, predicted objective step counts, and that experimentally increasing intrinsic motivation causally increased goal adherence.
Why it matters
These findings suggest that behavioral interventions should foster internal engagement with the activity itself rather than relying solely on external outcomes to maintain long-term habit change.
Limits
The abstract omits sample sizes, attrition rates over the 1-year study duration, effect sizes, and specific details about how intrinsic motivation was experimentally manipulated.