A novel paradigm investigates the ability to understand an agent's intended goal in children with autism (N = 25), typically developing children (N = 46), and adults (N = 16+12) by watching a non-human agent's kinematic properties alone. Computer animations depict a circle at the bottom of a U-shaped valley rolling up and down its slopes and getting closer to a target resting at the top of either side of the valley. The circle's persistent motion and improving attempts evoke the attribution of the intention to reach the target, regardless of whether the circle fails or attains its goal. Children with autism are as able as controls to infer an agent's intended-goal, disregarding its failure to reach the target. In addition, the study showed that the perception of persistent motion is a sufficient but not a necessary cue for very young children and children with autism to attribute intention to an agent, whereas adults consider the persistent motion cue as a sufficient and necessary cue to attribute intention to an agent.