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Category: Project

Description: Personality traits predict important life outcomes such as success in love and work life, well-being, health, and longevity. Given these positive relations to important outcomes, economists, policy-makers, and scientists have proposed intervening to change personality traits to promote positive life outcomes. However, non-clinical interventions to change personality traits are lacking so far in large-scale naturalistic populations. This study (N = 1,523) examined the effects of a 3-month digital personality change intervention using a randomized controlled trial (RCT) and the smartphone application PEACH (PErsonality coACH). Participants who received the intervention showed greater self-reported changes compared to participants in the waitlist control group who had to wait one month before receiving the intervention. Self-reported changes aligned with intended goals for change and were significant for those desiring to increase on a trait (d = 0.52) and for those desiring to decrease on a trait (d = -0.58). Observers such as friends, family members or intimate partners also detected significant personality changes in the desired direction for those desiring to increase on a trait (d = 0.35). Observer-reported changes for those desiring to decrease on a trait were not significant (d = -0.22). Moreover, self- and observer-reported changes persisted until three months after the end of the intervention. This work provides the strongest evidence to date that normal personality traits can be changed through intervention in non-clinical samples.