Raj was very distracted by his toy bunny when his mother was trying to get him dressed in the morning, so his mother took the bunny and put it behind the couch pillow. Raj crawled over to the couch and moved the pillow to get the bunny. According to Piaget, what cognitive advance has Raj developed?

Object permanence

Explanation: In the scenario above, it could be said that Raj has developed the cognitive ability to deduce that the existence of an object does not cease even when it isn't visible. This is evidenced by Raj's decision to crawl up and locate the hidden toy. This phenomenon according to paiget is developed during the sensorimotor stage of child development usually between 18 to 24 months of age. When object permanence is developed in a child, inability to see, hear or feel an object will no longer translate to non-existence of such object.

answer; when one group has an extremely high score at pretest;