Which developmental stage involves a child recognizing and labeling themselves as a boy or a girl?

The correct answer is gender identity because this developmental stage specifically refers to a child's recognition and understanding of their own gender. Typically occurring between the ages of 2 and 3, children begin to label themselves as either a boy or a girl, which marks the formation of their gender identity. This concept encompasses not just the labels, but also the internal sense of being male, female, or something else entirely.

In contrast, gender constancy relates to an understanding that gender remains consistent over time and across situations, which develops later. Gender role understanding involves grasping the societal expectations associated with being male or female, and tends to emerge after the establishment of gender identity. Gender expression refers to how individuals present their gender to the outside world, which can include clothing, behavior, and interests, and is influenced by personal choices and cultural norms rather than being a fundamental recognition of one's gender. Thus, gender identity is the foundation upon which these other concepts build.