“…o date, most research on youth sport has focused on parent involvement, socialization, and influence (e.g., Coakley, 2006;Fraser-Thomas, Côté, & Deakin, 2005;Knight, Dorsch, Osai, Haderlie, & Sellars, 2016;Ullrich-French & Smith, 2006). Yet, consistent with a family systems perspective (e.g., Cox & Paley, 1997), in that multiple family relationships should be examined in order to gain a better understanding of the phenomena being studied, scholars have called for further investigation into the role that siblings play in shaping youth's interests and T participation in sports (Blazo, Czech, Carson, & Dees, 2014;Côté & Hay, 2002;Davis & Meyer, 2008;Trussell, 2014).…”