Related terms include developmental psychology, referring to development throughout the lifespan, and pediatrics, the branch of medicine relating to the care of children.Developmental change may occur as a result of genetically-controlled processes known as maturation, or as a result of environmental factors and learning, but most commonly involves an interaction between the two.In addition to symbolism, children start to engage in pretend play in which they pretend to be people they are not (teachers, superheroes).In addition, they sometimes use different props to make this pretend play more real.Each system contains roles, norms and rules that can powerfully shape development.Since its publication in 1979, Bronfenbrenner's major statement of this theory, The Ecology of Human Development has had widespread influence on the way psychologists and others approach the study of human beings and their environments.It may also occur as a result of human nature and our ability to learn from our environment.
Piaget believed the origin of knowledge came from Psychology, so he traveled to Paris and began working on the first “standardized intelligence test” at Alfred Binet laboratories; this influenced his career greatly.
Formal operations: (about early adolescence to mid/late adolescence) The final stage of Piaget’s cognitive development defines a child as now having the ability to “think more rationally and systematically about abstract concepts and hypothetical events”.
Some positive aspects during this time is that child or adolescent begins forming their identity and begin understanding why people behave the way they behave.
In this stage, knowledge of the world is limited but is constantly developing due to the child's experiences and interactions.
According to Piaget, when an infant reaches about 7–9 months of age they begin to develop what he called object permanence, this means the child now has the ability to understand that objects keep existing even when they cannot be seen.