Vygotsky, different from Piaget , his main focus is on the importance of social interaction, culture and language in a child's cognitive development. He brought up mainly five assumptions about how the social culture effect one's cognitive development.
Firstly, he argued that the elementary functions can only develop into higher functions via the input of culture which emphasizes the importance of cultural involvement during a child's cognitive development. (here the culture is thought as a body of knowledge)
The second assumption is that the child begins to interact with the world through its actions, while society places meaning on those actions through social interaction. For example, by the social interaction with aldults, the initial movement of a child will take on a new meaning: from simply trying to reach an object to communicate to an adult by pointing at it.
The third assumption is that the primary way we communicate with the world is by language but not physical gestures. As the Vygotsky placed the importance of language development as part of overall cognitive development, he also divided the language development into three stages:
○ Pre-intellectual social speech - while thought and language are working separately
○ Egocentric speech - while children are started to use their language to express their action and emotion but still egocentric and not good at communication
○ Inner speech - while children can collaborate their thoughts and language skillfully (in this stage, it develops their thinking and communication skills)
Moreover, Vygotsky also articulated the importance of culture through the zone of proximal development(ZPD) which means the distance between the child's current and potential abilities under adult supervision.
At last, Vygotsky's theory indicated that the scaffolding is the most constructive method for teacher and parents to deliver their knowledge according to his ZPD