Answer:
Centration
Explanation:
Concept of Centration describes the cognitive development of children in their pre operational stage that makes them to focus all of their attention on one aspect of a situation or problem neglecting others. This concept was proposed by swiss psychologist named Jean Piaget in 1941. He observed that children tends to develop interest and pay more attention to one relevant aspect of a problem or situation leaving out other aspect that may also be of relevance.
Diego focused more on the size of his sister's glass being taller than his thinking it contains more juice than his.