According to Adolph, Weise, and Marin (2003), “Motor development refers to changes in children's ability to control their body's movements, from infants' first spontaneous waving and kicking movements to the adaptive control of reaching, locomotion, and complex sport skills”. Click here for the full-resolution PDF of this chart. ReferencesAdolph, K. E., Weise, L., & Marin, L. (2003). Motor development. In L. Nadel, Encyclopedia of cognitive sciences (pp. 134-137). London: Macmillan-Reference