Elementary and Higher mental Mental Functions
Vygotsky's theory emphasizes the critical role played by the social world in facilitating the child's development. According to his theory, children generally internalize thought processes that first occur through interaction with others in the social environment. Qualitative transitions between elementary mental functions and higher mental functions occur because of shifts in the use of mediators such as language and other symbols. The acquisition and use of language plays a primary role in children's developing intellectual abilities.
The Zone of Proximal Development
Vygotsky's interest in the child's potential for intellectual growth led him to develop the concept of the zone of proximal development. In recent years this concept has led to the use of scaffolding, an instructional process in which the teacher adjusts the amount and type of support offered to the child to suit the child's abilities, withdrawing support as the child becomes more skilled.
The Role of Culture
Two principles of cultural influence Vygotsky's theory: First, cultures vary widely in the kinds of institutions and settings they offer to facilitate children's development, and second, in assessing children's cognitive development, unless we consider these variations and cultural contexts we may seriously underestimate children's cognitive development.
The Role of Language
Language plays an important role in Vygotskian theory. As children begin to use social speech, egocentric speech,and inner speech, they learn to communicate and to form thoughts and regulate intellectual functions.

 Aiding Children In Cognitive Development
o    According to Vygotsky's theory, we can aid children in cognitive development through the right interactions. Such suggestions include a structure learning environment in which we provide the child with aid and instructions tailored to the child's current abilities. Cooperative and interactive learning exercises are important during this process, as well as monitoring the child's progress closely. As the child gains more ability, we should turn more mental responsibility over to the child. Unlike Piaget's theory, which emphasizes peers as the major change agents in a child's cognitive development, with Vygotsky, adults are the most important source.