We examined the life span development of openness to experience and tested whether change in this personality trait was associated with change in cultural activity, such as attending the opera or visiting museums. Data came from the Dutch Longitudinal Internet Study for the Social Sciences panel, which includes 5 personality assessments across a 7-year period of a nationally representative sample of 7,353 individuals, aged 16 to 95 years. Latent growth curve analyses indicated that on average, openness remained relatively stable in emerging adulthood before declining in midlife and old age. At each stage of life, there were significant individual differences in openness development, and changes in openness were correlated with changes in cultural activity. Autoregressive cross-lagged analyses indicated that increases in cultural activity precipitated increases in openness, and vice versa. These culture-openness transactions held across different age and education groups and when controlling for household income. We found less consistent codevelopmental associations between cultural activity and the other Big Five traits. We discuss the implications of these results for personality development theory and the role of cultural investment in personality trait change.