“…In light of the fact that adults judge the same behavior as either aggressive or not depending on the sex of the rater (Henry & Piercy, 1984; Pellegrini, 2011) and that multi-informant studies reduce bias in data (Tackett & Ostrov, 2010), future studies should include both mothers and fathers rating the behavior of their children. An additional advantage of this approach is that several studies have emphasized the value of multi-informant approaches (Ostrov, Ries, Stauffacher, Godleski, & Mullins, 2008; Tackett, Waldman, & Lahey, 2009).…”