This document summarizes key aspects of development in toddlerhood (ages 1-3 years old). It discusses cognitive, physical, social, emotional, and moral development. Some main points include: toddlers develop object permanence and telegraphic speech; their physical skills improve with running, jumping and grasping; socially they begin play with others and identify with same-sex parents; emotions are fully expressed through affection, jealousy, and seeking attention.