Despite increasingly delaying marriage and childbearing over the past few decades, young adults have become more likely to experience multiple parenting and family roles by the age of thirty—which could have long-term consequences for how successfully they can navigate those sometimes conflicting roles. Comparing data from the 1979 and 1997 cohorts of the National Longitudinal Survey of Youth, Lawrence Berger and Sharon Bzostek find in a recent study that young adults’ relationship and parenting histories are increasingly complicated.

For the sake of background, the 1979 cohort was made up of people born in the late 1950s and early 1960s (younger Baby Boomers), and the 1997 cohort of those born in the early 1980s (younger members of Generation X or the oldest Millennials). A few differences between the two groups stand out.

Those in the more recent cohort were less likely than their predecessors to have become parents by age thirty: 60.6 of the former were parents by that time, and 67.1 percent of the latter. Those who had a child by age thirty became far more likely to do so outside of marriage, however: 74 percent of younger Boomers who had become parents by age 30  were married at the time, vs. just 45 percent of their Gen X/Millennial counterparts.

The declining likelihood of having one’s first child in marriage makes for increasingly complicated families. Berger and Bzostek examined the two cohorts’ likelihood of experiencing multiple family roles by age thirty; the categories included “single, married, or cohabiting with resident biological children; single, married, or cohabiting with resident social children; and single, married, or cohabiting with nonresident biological children.” Although, again, young adults have become less likely to be (biological) parents by age thirty, they have become more likely overall to fill more than one of those parenting roles by the same age. Specifically, 13 percent of the 1979 cohort had experienced more than one parental role (filling them either simultaneously or sequentially) by thirty, vs. 18 percent of the 1997 cohort, an increase of about 38 percent in the space of a single generation.

The declining likelihood of having one’s first child in marriage makes for increasingly complicated families.

After discussing these findings, Berger and Bzostek explore their likely implications through the lens of identity theory. Identities, they explain, “are the meanings that define individuals—to themselves and others—in their social roles.” They evolve through social interaction, as “individuals attempt to create shared meaning vis-à-vis their social roles.” Having one’s identity as a parent or spouse or romantic partner) affirmed or “verified” by others is psychologically beneficial and reinforces group bonds. When one’s identity is questioned or undermined, on the other hand—when one fails to “achieve identify verification”—one is more apt to experience “(dis)stress, anxiety, and internal conflict.” In an attempt to alleviate these emotions, individuals may seek to alter their behaviors in order to achieve identity verification; failure in that attempt may lead to worse self-esteem and impact their future behavior.

Berger and Bzostek then apply these principles to how young adults navigate their roles  as romantic partners and parents. They believe individuals occupying multiple family roles—for example, acting as a residential parent to one biological child and a non-residential parent to a second—will experience greater identity conflict as they attempt to balance unclear or conflicting obligations and expectations in their various roles.

It’s easy to imagine why. The responsibilities entailed in marriage and biological, residential parenthood are, though perhaps difficult to juggle, clear; the responsibilities of an unmarried cohabiting partner, nonresidential parent, and residential step-parent are not. A nonresidential parent, that parent’s ex-partner, and that ex-couple’s child may all have different expectations of the nonresidential parent’s duties. As a general principle, the researchers believe, “the extent to which a particular type of relationship is institutionalized—and, thereby, elicits mutual understanding and role expectations—is likely to be inversely associated with identity role conflict.”

‘Lower levels of identity verification in complex families are likely to be associated with poorer individual and family functioning.’

Navigating less institutionalized relationships is inherently more difficult. No matter how hard one tries, natural limits on time and resources mean it may not be possible to satisfy all of one’s (biological or step-) children. A partner or ex-partner may respond by undermining, rather than affirming, one’s identity as a parent, leading to psychological distress and possibly disengagement from the roles of partner and parent. . . which can, in turn, contribute to the breakdown of both the romantic and the parent-child relationship. After the breakdown, the original discouraged parent may begin a new relationship and have a new child in the hopes of a fresh start. A cycle can set in as identity conflict and dissatisfaction in family roles lead to behavior that flouts the expected norms for a given role, which then leads to further relationship and identity conflict.

As Berger and Bzostek sum up their predictions, “because identity verification is associated with psychological functioning, as well as ongoing behaviors and relationship quality, lower levels of identity verification in complex families are likely to be associated with poorer individual and family functioning. This may (adversely) influence future identity-role behaviors and the well-being of both parents and children.”

Given the increasing prevalence of family complexity, the researchers call in their conclusion for “a substantial shift in how policies approach families and family functioning” when it comes to welfare programs, domestic partner benefits, pensions, parental leave, child support, and more. As they suggest, however, with their mention of “conflicting principles and inevitable trade-offs on issues of equity, adequacy, affordability, and outcomes from multiple perspectives,” a shift of that nature will be tough even to imagine, much less implement.