Variance Distribution in Sibling Relationships: Advantages of Multilevel Modeling Using Full Sibling Groups

• DOI: http://doi.org/10.1111/famp.12157
• Date: 01 March 2017
• Author: Karyn Marciniak
• Published date: 01 March 2017

Variance Distribution in Sibling Relationships:

Advantages of Multilevel Modeling Using Full Sibling

Groups

KARYN MARCINIAK*

The majority of research on sibling relationships has investigated only one or two

siblings in a family, but there are many theoretical and methodological limitations to this

single dyadic perspective. This study uses multiple siblings (541 adults) in 184 families,

where 96 of these families had all siblings complete the study, to demonstrate the value in

including full sibling groups when conducting research on sibling relationships. Two

scales, positivity and willingness to sacrifice, are evaluated with a multilevel model to

account for the nested nature of family relationships. The distribution of var iance across

three levels: relationship, individual, and family are computed, and results indicate that

the relationship level explains the most variance in positivity, whereas the individual level

explains the majority of variance in willingness to sacrifice. These distributions are

affected by gender composition and family size. The results of this study highlight

an important and often overlooked element of family research: The meaning of a scale

changes based on its distribution of variance at these three levels. Researchers are

encouraged to be cognizant of the variance distribution of their scales when studying

sibling relationships and to incorporate more full sibling groups into their research

methods and study design.

Keywords: Sibling Relationships; Multilevel Modeling; Variance; Sacrifice; Positivity

Fam Proc 56:189–202, 2017

Sibling relationships can be the most long-lasting relationships in one’s life (Cicirelli,

1991) and remain important and influential throughout adulthood (Lee, Mancini, &

Maxwell, 1990; Stocker, Lanthier, & Furman, 1997). Sibling relationships in larger fami-

lies (e.g., more than two siblings) create even more opportunities for influence, interaction,

and complexity.

There are numerous theoretical and methodological benefits to studying variations of

all dyads within sibling relationship groups (Crouter, Helms-Erickson, Updegraff, &

McHale, 1999; Riggio, 2006; Scharf, Shulman, & Avigad-Spitz, 2005). However, this varia-

tion in the quality of each of one’s multiple sibling relationships has rarely been explored

(Shortt & Gottman, 1997). Even with the increased use of multilevel modeling in sibling

research, very few of these studies collect information about more than one siblin g dyad

per family (some exceptions: Jenkins, Dunn, O’Connor, Rasbash, & Behnke, 2005; Jen-

kins, Rasbash, Leckie, Gass, & Dunn, 2012; Meunier, O’Connor, Boyle, & Jenkins, 2013).

Even fewer study all siblings in the family, assess the variance distribution between rela-

tionship, individual, and family levels, or investigate sibling relationship posit ivity, as this

study does.

*No affiliation.

Correspondence concerning this article should be addressed to Karyn Marciniak, 101 West 68th St Apt

3C, New York, NY 10023. E-mail: karyn.marciniak@gmail.com

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Family Process, Vol. 56, No. 1, 2017 ©2015 Family Process Institute

doi: 10.1111/famp.12157