Imitative deficits have been associated with autistic spectrum disorder (ASD) for many years, most recently through more robust methodologies. A fresh, systematic review of the significance, characteristics, and underlying mechanism of the association is therefore warranted. From 121 candidates, we focused on 21 well-controlled studies involving 281 cases of ASD. Overall, children with ASD performed worse on imitative tasks (Combined Logit p value < .00005).="" the="" emerging="" picture="" is="" of="" delayed="" development="" in="" imitation,="" implicating="" a="" deficit="" in="" mapping="" neural="" codings="" for="" actions="" between="" sensory="" and="" motor="" modalities,="" rather="" than="" in="" motivation="" or="" executive="" function.="" we="" hypothesise="" that="" asd="" is="" characterised="" by="" abnormal="" development="" of="" these="" mappings,="" such="" that="" they="" are="" biased="" towards="" object-oriented="" tasks="" at="" the="" expense="" of="" those="" required="" for="" action="" imitation="" per="">