"In society at large, lives have been drastically altered over this century—as a consequence of increased longevity, advances in science and education, the gender revolution, improvements in public health, and other historical trends and events—but numerous inflexible social structures, roles, and norms have lagged behind. There is a mismatch or imbalance between the transformation of the aging process from birth to death and the role opportunities or places in the social structure that could foster and reward people at the various stages of their lives. While the twentieth century has experienced a revolution in human development and aging, there has been no comparable revolution in the role structures of society to keep pace with the changes in the ways people grow up and grow old. The lag involves not only institutional and organizational arrangements, but also the many aspects of culture that, in addition to being internalized by people, are built into role expectations and societal mores and laws. For the future, then, structural changes will be needed if people are to find opportunities to spread leisure and work, as well as education, more evenly over the life course, and to make room for family affairs." —from Age and Structural Lag