I've blogged before about the differences between individuals with Autism Spectrum Disorders and Neurotypicals with respect to response to reinforcement. A mistaken notion, though, is that individuals with ASD's are indifferent to social reinforcement and praise... they may like it, but don't have the skills to produce it (you know, basic social stuff like make eye contact, smile at people, say reinforcing things to others). The mistake caregivers and others may make, then, is to give up and stop delivering high levels of praise and other positives (who reinforces the reinforcer?).
My friend Andy Jacobs passed this one on to me from Amman, Jordan, where he heads up a big film program. It's funny and instructive at the same time and reminds us all to keep up our high rates of reinforcement.