Personality interventions are a field of growing interest, as many people want to change aspects of their personality and personality trait changes promise to positively impact important life outcomes. Although initial research shows that personality interventions can be successful in eliciting lasting trait changes, the strategies, timing, and context of effective personality interventions remain unclear. A careful examination of how these characteristics would advance intervention effectiveness and theoretical models of volitional personality change. We used intensive longitudinal data from the Changing How I Live Life (CHILL) Study to examine the effects of different intervention strategies and their timing and situational context on intervention adherence, satisfaction, and changes in momentary positive affect as proximal intervention outcomes. The CHILL Study is a multi-method intervention study combining experience sampling methods and mobile sensing to investigate the effects of a smartphone intervention to decrease neuroticism (N = 399; 39,878 assessments). Intervention strategies that targeted the state level of neuroticism had more positive effects on people’s momentary affect than habit-level strategies, providing novel insights into the mechanisms of successful personality change. Furthermore, effects differed depending on the timing and situational context of intervention prompts, pointing to possibilities of optimizing the timing of personality interventions. For example, people were more likely to adhere to intervention prompts in quieter environments or at home. Together, these findings inform theoretical models of personality trait change and can be used to guide the development of effective and refined personality interventions.
Haehner et al. (Mon,) studied this question.