“…The opportunity to choose, in general, is usually reinforcing because it results in greater access to items and contexts that are momentarily or typically valuable to the person choosing (Fisher & Mazur, 1997). Furthermore, studies on the value of choosing show that the opportunity to choose, in and of itself, is highly reinforcing, in that children will work much more for conditions involving the opportunity to choose even when the same outcome is available for much less effort (Schmidt, Hanley, & Layer, 2009;Thompson, Fisher, & Contrucci, 1998;Tiger, Hanley, & Hernandez, 2006).…”