The Theory of Cognitive development offered by Jean Piaget is often criticized by more recent psychologists who claim it underestimated the cognitive skills of younger children and overestimated the abilities of adolescents relative to adults. However, if the test of conservation he conducted is attempted - filling a glass of water and then transferring the water to another container of equal size and asking "which has more water, this or the other glass?", on children prior to the operational stage they normally will be unable to answer or will answer incorrectly due to, most likely, centration
In Piagetian theory, the third stage of development, from approximately seven to eleven years of age, in which thought is logical when stimuli are physically present.