Chimerism is what happens when cells from one twin are present in the other. For example, white blood cells with Y chromosomes would be found in the female twin. Vigier et. al, 1989.
Piaget's theory of cognitive development. Piaget's theory of cognitive development is a comprehensive theory about the nature and development of human intelligence. It was first created by the Swiss developmental psychologist Jean Piaget (1896â1980).
Jean Piaget's Theory Of Cognitive Development. Jean Piaget is perhaps one of the most well-known and influential child development specialists. His work was first published during the 1920's, but his theory of cognitive development continues to influence contemporary researchers and clinicians. Piaget's identified five characteristic indicators of adolescent cognitive development and named them as follows: 1) formal operations, 2) hypothetico-deductive reasoning, 3) propositional thought, 4) the imaginary audience, and 5) the personal fable.