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).
Cognitive theory is an approach to psychology that attempts to explain human behavior by understanding your thought processes. For example, a therapist is using principles of cognitive theory when she teaches you to how to identify your maladaptive thought patterns and transform them into constructive ones.