Objective We examined adult children's concurrent ties to biological fathers and stepfathers. Three mechanisms potentially determining the strength of father-child and stepfather-child ties were tested, namely, investment, interdependence, and substitution. Background As most research studied father-child and stepfather-child ties separately, our knowledge about the potential substitution dynamics between the two ties is limited. Method We used the Dutch Ouders en Kinderen in Nederland (OKiN) survey, which features an oversample of individuals, aged 25-45, who did not live with their two biological parents when growing up (N = 1,183; M-age = 31.89 [SD = 5.13]; 56% female). OKiN includes information on adults' relationships to all parent figures in their lives. Non-recursive structural equation models were applied to account for the bidirectional influence between children's ties to biological fathers and stepfathers. Results Our findings suggested that the quality of the two father-child ties are interrelated, that is, we found a small substitution effect (i.e., adult children were more likely to "choose" one father in the presence of both). We also found that the quality of father-child and stepfather-child ties was associated with the length of the parental investment period (i.e., investment). In addition, bonds with stepfathers were positively associated with the attitudes of the two fathers toward each other, while bonds with both fathers were associated with the quality of the tie between the biological parents (i.e., interdependence). Conclusion Overall, the weak substitution dynamic that we found implied that a poor tie with one father can partly be substituted by being close to another father.
