Which of the following is NOT one of the four stages of Piaget's cognitive development theory?

The correct response identifies "Developmental" as not one of the four stages of Piaget's cognitive development theory. Jean Piaget, a prominent Swiss psychologist, formulated a comprehensive theory detailing how children progress through specific cognitive stages as they grow. These stages are distinctly defined and help in understanding how children's thinking evolves over time.

The four stages of Piaget's theory include:

1. Sensorimotor Stage (birth to 2 years) – In this stage, infants learn about the world through their senses and actions. They discover the concept of object permanence and begin to understand that objects continue to exist even when they are not visible.

2. Preoperational Stage (2 to 7 years) – During this stage, children start to engage in symbolic play and learn to manipulate symbols but do not yet understand concrete logic. They are egocentric and struggle to see things from perspectives other than their own.

3. Concrete Operational Stage (7 to 11 years) – In this phase, children begin to think logically about concrete events. They grasp the concepts of conservation, time, space, and quantity but struggle with abstract or hypothetical concepts.

4. Formal Operational Stage (12 years and up) – Here, individuals develop the ability to think abstractly