Half-Sibling Effects on Other Children
Several relatively recent studies have explored the effects of having a half-sibling on children’s well-being. Generally, children in simple stepfamilies (no half-siblings) are compared to children in blended stepfamilies (with half-siblings) and, less often, to children in nuclear families. Sometimes, mutual children are compared to their half-siblings on a variety of standard outcome measures (e.g., academic performance, internalizing and externalizing behaviors, substance use, and interpersonal relationship quality).
Although the findings of these studies are not homogeneous, most report that stepchildren who have half-siblings have worse outcomes on a variety of measures than stepchildren who do not have half-siblings (Evenhouse & Reilly, 2004; Gennetian, 2005; Ginther & Pollak, 2004; Halpern-Meekin & Tach, 2008; Harcourt et al., 2015 ; Strow & Strow, 2008; Tillman, 2008). A few researchers, however, report no differences (Bobbitt-Zeher & Downey, 2012; Yuan, 2009), and one study found that children in blended stepfamilies fared better than did children in simple stepfamilies, indicating that half-siblings moderated the negative effects of living with a stepparent (Evenhouse & Reilly, 2004) . One study found negative halfsibling effects for European American but not African American stepfamilies, which suggests that social environments and culture may play roles in these family dynamics (Harcourt et al., 2015). These studies are based on genetic theories or stress models, mentioned earlier in this chapter.