Piaget is known for his stages of cognitive development. These stages include: sensorimotor, preoperational, concrete operational and formal operational. With each stage, Piaget outlined a typical age range. For instance, the sensorimotor stage occurs in the first two years of life. During this stage, the child would experience the world through its actions and senses, which included: grasping, touching, looking, and the like. Although Piaget did believe children experienced egocentrism, he did not categorize it as its own stage. Instead, it is a developmental phenomenon of the preoperational stage. As a result, the choices egocentrism and object permanence are incorrect. The choices oral and id are stages in psychology; however, they are associated with Freud's psychoanalysis and are incorrect. 

Piaget's stages of cognitive development are as follows: sensorimotor, preoperational, concrete operational and formal operational. Piaget associated an age ranges for each stag that specific developmental phenomena occur at. During the first two years of life, a child will go through the sensorimotor stage where a child will experience the world through it senses (i.e. grasping and sight); therefore, object permanence occurs in the sensorimotor stage.

Piaget's stages of cognitive development are as follows: sensorimotor, preoperational, concrete operational and formal operational. Piaget associated an age ranges for each stag that specific developmental phenomena occur at. Preoperational stage occurs at the preschool age. At around 2 to 4 years of age, children Piaget theorized that children experience egocentrism. During this time, children have difficulty perceiving things from another's point of view. For example, a 3-year-old girl may cover her eyes with the intention of making herself invisible from her parents. As a result of her obstructed vision, she incorrectly assumes that her parents cannot see her.

Piaget's stages of cognitive development are as follows: sensorimotor, preoperational, concrete operational and formal operational. Piaget associated an age ranges for each stag that specific developmental phenomena occur at. At 2 to 7 years of age, Piaget believed that a child encounters the preoperational stage. At this point, a child is believed to be too young to preform mental operations (i.e. it is difficult for a child to imagine a situation and mentally reverse the action). This was observed in Sally's example. She decided that the narrow glass had more liquid despite the fact that both glasses contained the same amount of juice. In Sally's case, she demonstrates what Piaget thought as a lack of the concept of conservation. She cannot identify that despite the change in shape of the glass, the amount of juice is the same. 

Piaget's stages of cognitive development are as follows: sensorimotor, preoperational, concrete operational and formal operational. Piaget associated an age ranges for each stag that specific developmental phenomena occur at. At 6 to 11 years of age, Piaget believed that a child encounters the concrete operational stage. At this point, a child is believed to be old enough to grasp mathematical transformations and mental operations (i.e. they can imagine a situation and mentally reverse the action). This was observed in Kevin’s example. In Kevin’s case, he decided that both glasses contain equal quantities of juice. In this scenario, Kevin has a clear grasp of the concept of conservation, something that may not be true for a child in the preoperational stage. 

Piaget's stages of cognitive development are as follows: sensorimotor, preoperational, concrete operational and formal operational. Piaget associated an age ranges for each stag that specific developmental phenomena occur at. A child typically experiences the sensorimotor phase for the first two years of life. This stage is followed by the preoperational stage at 6 or 7 years of age. The preoperational stage is replaced by the concrete operational stage from the ages of 7 to 11 years. Last, the child will enter into the formal operational stage at age 12. This final stage continues throughout adulthood and is associated with a focus on abstract reasoning. At this stage, the individual will encounter abstract logic and the potential for mature moral reasoning.

Piaget's stages of cognitive development are as follows: sensorimotor, preoperational, concrete operational and formal operational. Piaget associated an age ranges for each stag that specific developmental phenomena occur at. At 7 to 11 years of age, Piaget believed that a child encounters the concrete operational stage. At this point, a child is believed to be old enough to grasp mathematical transformations and mental operations. The child can think logically about concrete events. This represents Cameron’s developmental stage. On the other hand, at age12 through adulthood, the child enters the formal operational stage. By this time, the child can engage in abstract thinking and has the potential for mature moral reasoning. At this point, the individual can engage in hypothetical situations and deduce what the consequences may be. As a result Gary’s ability clearly characterizes Piaget's formal operational stage. 

Object permanence is defined as the understanding that objects continue to exist even if one cannot see them. According to Piaget, infants being to develop this at around 7-9 months of age in the sensorimotor stage.

Object permanence is the understanding that even though an object has disappeared from view, that disappearance is probably temporary: the object has not disappeared totally from existence. Infants do not achieve this understanding until around eight months of age. Because of this, the baby girl likely believes her father no longer exists when he disappears from view, which is upsetting.

The adolescent brain continues to develop into the early to mid twenties. In fact, the prefrontal cortex is the last brain region to fully develop, but it is primarily responsible for executive functions among other cognitive skills. This explains Jackie's inability to inhibit and think through long-term consequences of her actions.