The author examined gender roles among midlife managers over a 4-year period and the effects of career experiences. The findings supported a conceptualization of personality as relatively enduring but still open to change. Masculinity and femininity demonstrated differential stability and absolute stability, except in the case of women's femininity. Its magnitude decreased. At the same time, income change, promotion, and having a protege were associated with increased masculinity and income change with increased femininity. A new child also meant increased masculinity for men. Furthermore, income change, promotion, turnover, being mentored, and having a protege affected the relative placements of managers' scores over time. Many of the effects were different for men and women. The findings have important implications for adult development in the workplace.