The First Year at Work: A Three-Wave Longitudinal Study of Short-Term Changes in the Big Five Traits Among Emerging Adults

Personality—particularly the Big Five traits—shapes how emerging adults adapt to work, yet while longer-term personality development across emerging adulthood is well documented, far less is known about short-term changes during the transition into the first year of employment. Using a three-wave longitudinal design, we examined changes in the Big Five traits in 397 Japanese university graduates ( M _age = 22.19) across their first year at work. Latent growth modeling showed significant decreases in self-reported extraversion, agreeableness, and conscientiousness. Higher pre-employment organizational desirability was associated with a more favorable initial profile—lower neuroticism and higher extraversion and conscientiousness—but did not predict the rate of change in any trait. These findings identify the first year of employment as a period of meaningful change and highlight the value of a short-term perspective complementing long-term approaches. Whether these changes reflect genuine trait development or shifts in self-perception remains an open question.