Piaget's work demonstrated quite clearly that a child's representation of the world is different from that of an adult. For example, most adults realise that a volume of water remainds constant when poured into a taller, narrower container, even though its level is now higher. However, early in the preoperational period, children will fail to recognise this fact; they will say that the taller container contains more water. The ability to realise that an object retains mass, number or volume when it undergoes various transformations is called conservation; the transformed object conserves its original properties.
Babies recognising patterns
By 3 months, babies show clear signs of pattern recognition and the visual system develops quite rapidly.
Sir Michael Rutter - Romanian Orphans
Sir Michael Rutter and his colleagues examined the extent of 'developmental catch-up' in a group of 111 Romanian orphans adopted into English families within 24 months of being born. They found that at 4 years of age the Romanian orphans had 'caught up' developmentally with a control group of English adopted children.
Cognitive structures: According to Piaget, mental representations or rules, such as schemata or concepts, that are used for understanding and dealing with the world and for thinking about and solving problems.
Piaget - Formal operations
During the period of formal operations, which begins at about age 11, childen become capable of abstract reasoning. They can now think and reason about hypothetical objects and events.