The dependent variables were: (a) appropriate play, (b) stereotypy, and (c) parent ratings of each participant’s mood,
happiness and interest in play. Appropriate play was defined as the unprompted use of toys in a manner consistent with their intended function (Lang, Machalicek, et al., 2009). Additionally, in order to be scored as appropriate play, the behavior had to involve at least two actions consistent with a recognizable play scheme.