What cognitive milestone is characterized by a child's ability to separate self from objects?

The cognitive milestone associated with a child's ability to separate self from objects falls within the sensorimotor stage. This stage, which spans from birth to approximately 2 years of age, is crucial for early development as infants learn about the world through their senses and actions. During this period, children begin to understand the concept of object permanence, where they realize that objects continue to exist even when they cannot be seen. This understanding marks a significant advancement in their cognitive development, as they start to differentiate themselves from their environment and recognize their role in interacting with various objects around them.

The other stages mentioned have different focuses. The concrete operational stage, which occurs from about 7 to 11 years old, revolves around logical thinking and the ability to perform operations on concrete objects. The preoperational stage, typically from ages 2 to 7, is characterized by symbolic thinking and egocentrism but does not yet involve the clear separation of self from objects as foundationally established in the sensorimotor stage. The formal operational stage, starting around age 12, involves abstract thinking and problem-solving but is beyond the immediate concerns of separating self from objects seen during infancy.