“…Behavior analysts generally view perspective taking as a learned repertoire (Barnes-Holmes, McHugh, BarnesHolmes, & Barnes-Holmes, 2004). In a global sense, this idea is supported by the growing body of research showing that perspective-taking skills are influenced by environmental factors, such as the presence of siblings (e.g., Cassidy, Fineberg, Brown, & Perkins, 2005), family size (e.g., Jenkins & Astington, 1996), the relative age and gender of siblings (e.g., Ruffman, Perner, Naito, Parkin, & Clements, 1998), and the quality of sibling and maternal conversations about perspective taking (e.g., Foote & Homes-Lonergan, 2003;Peterson & Slaughter, 2003;Ruffman, Slade, & Crowe, 2002).…”