Answer:
Piaget's cognitive-dev theory
Step-by-step explanation:
Piaget's cognitive development theory explains the cognitive development of children in stages and therefore as they mature. This involves changes in cognitive abilities and cognitive processes as a person grows or matures.In Marcus's view from the question above, cognitive abilities are same for everyone and child's cognitive abilities improves and develops as the child grows. This is in harmony with Piaget's theory of cognitive development.