Individual and generational value change in an adult population, a 12-year longitudinal panel study.

A long-standing conundrum is whether age differences in personality are due to generation, or internal change with age. Using a representative sample from The Netherlands (N = 1599; aged 16-84 at the start), the current research focuses on human values (an important aspect of personality), following the same individuals for 12 years. We distinguish four generations, Silent-generation, Baby-boomers, Generation-X and Millennials. We found clear differences across generations in human values, with Millennials, e.g., valuing hedonism more than all other generations. Furthermore, value change over time was mainly evident in Millennials. Some values (achievement and conformity) were stable within individuals and between generations. Change over time across most values occurred mainly in Millennials, but not for all values. Some values were stable in adults (e.g., hedonism, conformity) while other values still increased (e.g., security, self-direction) or decreased (e.g., power, stimulation) in importance. In adults older than Millennials change decreased and change was absent in the oldest generation. Hence, age differences in values seem both due to generation, as well as internal change, although the latter mainly in young adults. These value changes over time may have implications for developments in societal values in the long run.