Throughout the series, several characters mention that Morty has a learning disability, and he often displays low self-esteem. Despite this, he's shown to be intelligent and resourceful at times and as the series progresses he learns how to use many of Rick's devices and even manipulates Rick into taking Jerry on an adventure. By the end of season three he displays an uncanny degree of common sense as well as a deep understanding of Rick's twisted mind, as seen in "Vindicators 3: The Return of Worldender".