Adulthood

Human development occurs within the context of family. Individuals' lives are intertwined with families. It is useful therefore to consider individual development and family development simultaneously, focusing upon the intersection of individual time, family time, and historical time (Hareven 1978). Change occurs at three different levels: the developing individual, dyadic relationships within the family, and the institution of the family ( Jerrome 1994). The family as a social group or institution moves through time in a constantly changing social and cultural environment. The family has a culture of its own that is sustained and elaborated upon by generations of members. Dyadic relationships within the family (i.e., parent and child, siblings) typically last across multiple decades and provide horizontal and vertical linkages in the family system. Change in individual family members, involving personality and family roles, are connected to their own (and other relatives') aging process. As Dorothy Jerrome (1994, p. 8) notes: "The family of childhood becomes the family of middle adulthood, which is replaced by the family of old age. The overlap in membership gradually diminishes until in the end the former group of relatives is completely replaced. Arguably, it is still the same family, though, through the handing down of traditions, family 'ways' and items or objects which link present generations to previous ones."

Within industrialized societies, demographic and social changes of the twentieth century have had profound effects on the family as an institution, dyadic relationships, and members' roles. The shift from high mortality–high fertility to low mortality–low fertility has heightened interest in adult intergenerational relationships. Increased life expectancy coupled with declining fertility has led to the verticalization of the family—a pattern of an increasing number of generations in a family accompanied by a decreasing number of members within a single generation (Bengtson, Rosenthal, and Burton 1990). Thus, family relationships are of unprecedented duration. Parents and children now share five decades of life, siblings may share eight decades of life, and the grandparent-grandchild bond may last two or three decades. Increases in life expectancies have led to middle age becoming the life stage in which adult children typically confront parental declining health and death. About 40 percent of Americans enter midlife with both parents alive, whereas 77 percent leave midlife with no parents alive.

The verticalization of the family in developed countries has also been accompanied by increased educational and labor force opportunities for women, technological advances in reproductive choice, and greater public acceptance of diverse lifestyles and family choices. Adults face unprecedented choices about whether and when to marry, whether to remain married, divorce, or remarry, and whether and when to have children. There is a growing heterogeneity in life course transitions as both men and women move in and out of cohabitation, marriage, parenthood, school, employment, and occupational careers at widely disparate ages and in different sequences. Phenomena that were once clear markers of young adulthood, such as marriage and parenthood, are therefore less predictable and there is greater diversity in the structure of families.

One phenomenon of the changing age structure of families that has received growing attention is the sandwich generation, those adults who find themselves caring for aging parents while still caring for their own children. Recent studies have raised questions, however, about the size of this phenomenon. A study of twelve European Union countries found that only 4 percent of men and 10 percent of women aged forty-five to fifty-four had overlapping responsibilities for children and older adults who required care (Hagestad 2000). Yet, others stress that the definition of caring that is employed greatly influences the obtained percentage of sandwiched adults. For example, the previously described emerging adult life stage (a prolonged period of independent role exploration) has led to a prolonged parenting phase for many midlife adults. Approximately one-third of U.S. parents aged forty to sixty currently coreside with an adult child (Ward and Spitze 1996).