Effects of enthusiastic and non-enthusiastic voice in praise on the behavior of children with autism and typically developing children

Behavioral intervention manuals for children with autism spectrum disorder (ASD) commonly recommend that praise should be delivered in an enthusiastic tone of voice. Only a few studies, however, have explicitly tested this assumption, and results have been mixed. This study therefore compared the effects of enthusiastic and non-enthusiastic tone of voice in praise on the behavior of children with ASD. We also examined how typically developing (TD) children responded to enthusiastic and non-enthusiastic praise. Participants were 21 children with ASD matched on developmental age with the chronological age of 20 TD children. The effects of enthusiastic and non-enthusiastic praise were assessed using an application on a tablet computer designed to isolate tone of voice as a variable in vocally delivered praise. Two buttons produced the same six praise statements, one with an enthusiastic tone of voice and one with a neutral tone of voice. Results showed that the children with ASD, on average, allocated more responding to the square on the tablet computer producing enthusiastic praise as compared to the square producing non-enthusiastic praise. In addition, higher rates of responding to non-enthusiastic praise correlated positively with higher IQ, suggesting that non-enthusiastic praise was more effective for children with ASD with higher cognitive scores. The TD children, in contrast, did not allocate more responding to either the squares, suggesting that tone of voice in praise was not an important variable for the behavior of TD children.