topics: |  psychology | biography | cognitive

Unlike psychologists before him who denied capabilities in children, Piaget,
one of the most influential child psychologists of the twentieth century,
focused on the cognitive abilities of infants, which led ultimately to the
field of developmental psychology.  Piaget stressed that development is based
on biological capabilities and their interaction with the environment.  He
proposed four major stages of development through which all children progress
at varying ages:

1. sensorimotor stage: lasts from birth to 18 months. During this stage,
   motor skills, perceptions, and sensations are emphasized.  preoperational,
   concrete operations, and formal operations. The
2. preoperational stage occurs from 18 months to seven years and is
   characterized by advances in symbolic thought, language, and an egocentric
   view.
3. Concrete operations stage, which occurs between ages seven and eleven,
   involves advances in conservation and basic concepts.
4. The last stage of development, formal operations, occurs from age eleven
   to adulthood. During this stage, abstract thinking and logical reasoning
   skills are formulated.
Following Piaget, there was much development of these ideas in Russia.
Vygotsky (1956, 1960) who formulated an idea on the social nature of the
child's mind and a role of instruction and communication with an adult for
his mental growth. Vygotsky believed that the psychological development of a
child included aspects of biology and social conditions. Although environment
factors play a major part in the development, the social environment also
plays a major part in it as well. Adaptation includes counteraction against
elements in the environment, and the interrelations between the child and
his/her environment, which are regulated through upbringings. Upbringing is
determined by society, culture, tradition, morals, and ideals (1972).