Personality and epigenetic aging: A multi-cohort and multi-clock study.

Epigenetic clocks are measures of biological aging related to critical health outcomes, including mortality. The present study examined whether personality traits are related to epigenetic aging. Participants (Age range: 17-98 years, N > 6000) were from the Health and Retirement Study, the Midlife in the United States study, and the UK Household Longitudinal Study. Measures of personality traits, demographic factors, first-generation (Hannum, Horvath), second-generation (PhenoAge, GrimAge), and third-generation (DunedinPoAM38/DunedinPace) epigenetic clocks were obtained in each sample. The strongest evidence emerged for conscientiousness: The meta-analysis indicated that higher conscientiousness was associated with a slower epigenetic aging as indexed by second- and third-generation clocks. The other traits were not consistently associated with the five clocks. Surprisingly, moderation by age indicated agreeableness was associated with slower epigenetic aging among relatively older but not younger adults. The present study suggests that conscientiousness is associated with slower epigenetic aging, particularly second and third-generation clocks trained on health-related outcomes.