Answer:
The best answer to the question: Which is true about the brothers according to Jean Piaget´s Theory of Cognitive Develpment? would be: David, the younger of the two brothers is at the Preoperational Stage of Development, while his brother Paul, the older of the two, seems to have reached the Concrete Operational Stage of Development.
Step-by-step explanation:
For a long time, before thinker Jean Piaget appeared in the picture, people used to believe that little children were simply a younger, and less intelligent version, of an adult. As such, it was also believed that their minds, and therefore their cognitive development, would improve as they grew. However, Piaget changed that concept by proposing his famous, and up until today still accepted, Theory of Cognitive Development. This theory recognized that childrens´ minds develop independently, and differently from what adults expect, and they do so through their experience of the world around them, given the skill sets and the development of their own brains and bodies. From this theory 4 stages were thus recognized: Sensorimotor (birth to 2 years of age), Preoperational Stage (2 to 7), Concrete Operational (7 to 11) and the Formal Operational Stage (12 and up).
David cannot yet fathom that the same amount of Play-doh is present in both the ball and the hotdog shape, even though this is true, because the hotdog "seems" bigger than the ball. However, Paul, whose brain is more developed and his senses are too, now understands that the same material, and in the same amount, remains in both shapes. David is in the preoperational stage, while Paul has entered the Concrete operational.