Using this approach, we could straightforwardly compare the relative
rank of the romantic partner with the rank of the sibling in the attachment hierarchy as a function of sibling type.
Further, regarding the sixth question, the three sibling types also differed significantly in the assigned
rank of their romantic partner, χ2 (2) = 47.18, p <.001.
The reason for conflict is that
the rank of the romantic partner is definitely not on top of the attachment hierarchy (as in a relationship with an NT) sibling, nor is the partner definitely beyond the twin (as in a relationship with an MZ twin).
Not exact matches
To do so, we compared monozygotic (MZ), dizygotic (DZ) and non-twin (NT) siblings in the way they form the relative
rank of the sibling and the
romantic partner in their attachment hierarchies.
They were advised to make a
ranking in which the four targets (sibling, mother, father, and
romantic partner) were sorted according to the strength
of emotional connectedness to these persons.ii Low values (i.e., a high
rank) indicate a high level
of emotional connectedness
of the participant to the target person.
This equal
rank of the sibling and the
romantic partner in relationships with one DZ twin involved might be a source for open conflict.
Perhaps the attachment to the
romantic partner is equally strong independent
of sibling type, and the predicted effects solely lie on the different
rank of the sibling in the attachment hierarchy
of the participants (attachment to the
romantic partner MZ = DZ = NT).
Comparisons
of the
rank of the sibling and the
romantic partner in the attachment hierarchy within each sibling type revealed in line with the third prediction that MZ twins placed the twin, mean
rank = 1.42, SD = 0.76, significantly higher than the
romantic partner, mean
rank = 2.10, SD = 0.88, z = 4.59, p <.001.
Across all participants, the
romantic partner was on the top
of the attachment hierarchy, mean
rank = 1.78, SD = 0.93, followed by the sibling, mean
rank = 2.19, SD = 1.14, and the mother, mean
rank = 2.56, SD = 0.86.
As we focused our research on the relative
rank of the sibling and the
romantic partner in the attachment hierarchy, this research was not designed to test this mediational model.