In this article, I review evidence showing that early childhood is a normative time for gender rigidity across many domains, including appearance, play, peer preferences, and intergroup gender attitudes. Gender rigidity can be seen in children's adherence to what society deems appropriate, or avoidance of what society deems inappropriate, for their gender. Many aspects of gender typing show an intriguing curvilinear pattern of increasing rigidity followed by flexibility. I offer an explanation for this pattern, focusing on children's growing awareness, knowledge, and understanding of gender. These developing cognitions are theorized to motivate children to engage in active self‐socialization as they strive to adhere to gender norms. I suggest how we can understand variation in early gender rigidity and whether gender rigidity has implications for well‐being and achievement in life.