@cornbird Well, Piaget’s theory of cognitive development isn’t very continuous. He talks about how there are stages to development and you progress from one stage to the next – sensorimotor, preoperational, concrete operational, and formal operational. Kids in the later stages have cognitive abilities that younger kids don’t, obviously. He says that you can’t teach a preoperational kid to think like a concrete operational kid.
Each stage has different characteristics. So, for example, preoperational thinkers are static thinkers meaning they think it terms of permanent states. But older kids who aren’t in the preoperational stage anymore can grasp the idea of transformations. Preoperational kids are also egocentric thinkers. They think about things in terms of themselves and if you ask them to consider things from another persons point of view they just don’t understand. (Like looking at an object from your angle as opposed to mine. If you’re a preoperational thinker and I ask you what you think I see, you’d answer with what the object looks like from your angle, not mine. You just can’t understand that it might look different to me. [Look up Piaget’s three mountain task.])
Also, look up information about lack of conservation experiments. Those might give you some good information, but I’d rather not type all those out.
GOOD LUCK!