ABSTRACT
Sibling relationships are unique, involuntary family relationships that can last a lifetime. Many sibling relationships are intense, complex, and deeply affected by a shared family history (Mikkelson, 2006 ). Other siblings spend little time with each other, perhaps due to differences in age, geographic distance once they become adults, or living arrangements that separate step or half siblings after a divorce and remarriage. It does not take long to notice one theme in the research literature on siblings. That is, sibling interaction varies dramatically depending on factors such as age, sex, birth spacing, birth order, number of siblings, genetic relatedness, the family context within which they originate and exist, and differential treatment by parents.
