Although the birth of children brings stress to any marriage, children tend to stabilize a marriage and help prevent the likelihood of divorce, especially when a couple has several children. Children pose, however, a different dynamic in stepfamilies, judging from a study by Susan D. Stewart of Iowa State University that documents an inverse relationship between the high level of "boundary ambiguity" in such families and marital quality and stability.
Defining boundary ambiguity as a "lack of clarity as to who is in and who is out of the family," Stewart draws upon the 1988 National Survey of Families and Households to measure the extent of discrepancy between spouses in their perception of what children are "in" their respective families. In her sample of more than 3,350 families representing "first-married, remarried, and cohabiting couples with minor children from previous and current unions with minor step-, biological, or adopted children," the sociologist discovered that boundary ambiguity is significantly more prevalent in stepfamilies than in original two-parent families.
In her multivariate tests, couples with stepchildren were found to have almost three times the odds of boundary ambiguity than couples with only shared biological children. Couples with greater family complexity (having at least two sets of stepchildren and shared children) relative to couples with less complexity (only one set of stepchildren and no shared children) increased those odds of boundary ambiguity. While resident stepchildren lowered the odds, nonresident stepchildren raised the odds, as couples with two sets of nonresident children faced the strongest effect, 44 times the odds. Also contributing to the mix was the union status of the couple, as cohabiting couples faced 40 percent greater odds of boundary ambiguity than married couples.
While it did not appear to affect the perception of marital quality on the part of men, boundary ambiguity did stress women. Stewart found that wives in families with ambiguity reported significantly more disagreements with their husbands and significantly higher chances of separating than their peers in families with no ambiguity (p < .05 for both correlations). Both results included controls for family complexity and parental characteristics, including union status (cohabiting or married), previous marital status, age, race, and education.
While Stewart did not examine the impact of boundary ambiguity on children, her revelation that nonresident stepchildren are often "out of sight, out of mind" underscores that divorce and remarriage - while catering to the demands of adults - rarely serve the interests of their children.
