Anne Fleur Kortekaas-Rijlaarsdam

13 INTRODUCTION 1 reprimand (Ryan & Deci, 2000). Intrinsic motivation for schoolwork has been shown to improve academic performance indirectly, by increasing task engagement and by improving study stills (DiPerna, Volpe, & Elliott, 2005; Volpe et al., 2006) related to academic performance. Importantly, previous research has shown that children with ADHD show lower intrinsic motivation for schoolwork (Carlson, Booth, Shin, & Canu, 2002; Gut, Heckmann, Meyer, Schmid, & Grob, 2012), but that the relation between this type of motivation and academic performance is stronger in children with ADHD than in typically developing (TD) controls (Gut et al., 2012). Together, these results emphasize the importance of intrinsic motivation for schoolwork, especially in children with ADHD. In addition, performance of children with ADHD is highly dependent on external motivators such as reward and punishment (Luman, Oosterlaan, & Sergeant, 2005) and children with ADHD prefer immediate over delayed rewards (Sonuga-Barke, 2005). Thus, it is likely that children with ADHD are less motivated to perform a task that is not directly rewarding (academic task often do not include rewards or these rewards are delayed, e.g. grades, job perspectives). Hence, in addition to lower intrinsic motivation for schoolwork, children with ADHD are likely to show altered extrinsic motivation for schoolwork, due to their differential responses to reward and punishment. Related to this, perceived academic competence (the child’s beliefs about his or her own capacities and abilities) is theorized to precede intrinsic motivation (Deci & Ryan, 1985; Harter, 1981; Wigfield & Eccles, 2000), with higher academic competence increasing intrinsic motivation. Further, perhaps partly due to this increased intrinsic motivation, perceived academic competence has the potential to improve academic performance. The relationship between perceived academic competence and academic is reciprocal, meaning that higher perceived competence increases academic performance and better performance increases perceived competence (Guay, Marsh, & Boivin, 2003). As ADHD symptoms show a negative relationship with perceived academic competence (Scholtens, Rydell, & Yang-Wallentin, 2013), this lower perceived competence is likely to further contribute to the academic problems of children with ADHD. One way to increase motivation for academic performance is to give incentives. Incentives within classrooms often take form of feedback but sometimes also include for example points, stickers or grades. Such incentives have been widely shown to positively affect achievement and motivation for learning (Hattie & Timperley, 2007; Shute, 2008). Especially positive feedback (in comparison to negative feedback) can increase task interest and task persistence (Deci, Koestner, & Ryan, 1999; Fyfe & Rittle- Johnson, 2017). Motivational strategies such as praise and reward are an important stimulator within classrooms but feedback frequency in classrooms is low and not