Siblings, Half-Siblings, and Stepsiblings

Abstract What is the nature of sibling, stepsibling, and half-sibling relationships in stepfamilies? Data on the presence of stepsiblings and half-siblings in stepfami- lies is difficult to acquire but estimates are that nearly 15 % of all children live with a half-or stepsibling, and over 12 % live in complex stepfamilies in which they have both half- and stepsiblings. This complexity is important to address because it relates to family dynamics and children’s well-being. Theoretical perspectives on children’s sibling relationships in stepfamilies are presented, including: (1) parental resource/investment models, (2) sibling structure, (3) stress hypotheses, and (4) selection effects, Research on siblings in stepfamilies is in its infancy, but factors that influence relationships include: frequency of contact (do they share a residence), age differences, sex differences, and perceived equity of treatment by the step-couple.

Keywords Siblings • Stepsiblings • Half-siblings • Family complexity • Sibling structures • Selection effects • Parental resources • Parental investments

In addition to brothers and sisters they may have prior to their parents’ remarriages or repartnering, children may acquire stepsiblings and half-siblings. Children in stepfamilies may reside either full-time or part-time with any combination of siblings, stepsiblings, and half-siblings, or they may not live with them at all. Also children in stepfamilies may have half-siblings that are related to them but not genetically related to each other. In some stepfamilies, half-siblings and stepsiblings may never meet each other or have only limited encounters, and their age range is often greater than that of siblings.

Nearly 15 % of all children live with a half- or stepsibling (Kreider & Ellis, 2011). Data from US national studies generally indicate about 10 % of children reside with half-siblings (Ginther & Pollak, 2004) and about 19 % live with half-siblings, stepsiblings, or both (Yuan, 2009). As with other stepfamily relationships, data on the prevalence of stepsiblings and half-siblings are difficult to acquire, primarily because demographers generally focus on measuring households, and therefore nonresidential half- and stepsiblings seldom are counted. Attempting to account for all half- and stepsiblings, regardless of their residence, Bumpass (1984) estimated that two-thirds

© Springer Science+Business Media New York 2017 L. Ganong, M. Coleman, Stepfamily Relationships, DOI 10.1007/978-1-4899-7702-1_10

of the children in stepfamilies have either a stepsibling or a half-sibling. It should be noted that other family structures also contain half- and stepsiblings—using 2008 US data, Brown, Manning, and Stykes (2015) reported that 12.3 % of all children lived in complex families, which they defined as households in which children had halfsiblings, stepsiblings, or “other” unrelated siblings (i.e., not genetically or legally related through adoption). Of the children in complex families, 37.8 % were in “married biological families,” 28.7 % were in married stepfamilies, 7.7 % lived in cohabiting stepfamilies, and 21.8 % were from single parent households.