Final answer:
Piaget's stages propose that children start abstract thinking around age 11, develop skills in the same sequence, may show cognitive skills before they can express them verbally, and mastering object permanence can happen even in the early preoperational stage.
Step-by-step explanation:
Regarding Piaget's stages of cognitive development, the following is true:
- Children can communicate about abstract topics after they reach the formal operational stage, which typically starts around 11 years of age.
- Piaget's theory does suggest that all people develop through the stages in the same sequence.
- Cognitive abilities may sometimes develop earlier than Piaget initially theorized, and children can display understanding before they can verbally express it.
- Mastering object permanence can still occur within the preoperational stage, as this concept manifests early on in the sensorimotor stage.