Piaget Developmental Milestones. Birth through ages 18 24 months. Prior to the 20th century children were often seen simply as miniature versions of adults.
Variation in competence between child development milestones is strongly related to familiarity with a situation. Here s a list of developmental milestones. After observing children during a series of interviews during the 1920s noted swiss psychologist and philosopher jean piaget outlined the stages of childhood to explain human intellectual development.
In one experiment conducted by psychologist jean piaget preschool children were shown a diorama of three mountains each with a distinctive object on top.
He disagreed with the idea that intelligence was a fixed trait and regarded cognitive development as a process which occurs due to biological maturation and interaction with the environment. Toddlerhood 18 24 months through early childhood age 7. Piaget developed his theories by watching children and making notes about their progress. Cognitive development involves changes in cognitive process and abilities.