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).
Piaget's Stages of Cognitive Development. Jean Piaget was a developmental psychologist best known for his theory of cognitive development. Piaget's stages deal with the nature of knowledge (epistemology) and how humans come to gradually acquire it.See also: Erikson Stages.iaget's Stages of Cognitive Development. Jean Piaget was a developmental psychologist best known for his theory of cognitive development. Piaget's stages deal with the nature of knowledge (epistemology) and how humans come to gradually acquire it. See also: Erikson Stages.