1. Vygotsky’s Theory of Cognitive Development and scaffolding
Social Interaction and culture has a dramatic impact on cognitive development.
Cognitive processes (language, thought, reasoning) develop through social interaction.
Learning is largely mediated by social interaction of students and "More Knowledgeable Others" (e.g. teachers, parents, coaches, peers, experts, etc.)

2. Vygotsky’s Theory of Cognitive Development

3. Vygotsky's theories stress the fundamental role of social interaction in the development of cognition.
Vygotsky emphasised the role of culture and experience. Vygotsky believed that what drives cognitive development is social interaction – a child’s experience with other people. Culture shapes cognition.
The Zone of Proximal Development is the distance between a student’s ability to perform a task under adult guidance and/or with peer collaboration and the student’s ability solving the problem independently.
Vygotsky sees the Zone of Proximal Development as the area where the most sensitive instruction or guidance should be given - allowing the child to develop skills they will then use on their own - developing higher mental functions.
The idea is that a child is only able to take the next step in their cognitive development if another person – typically an adult – supports and prompts them to do so. This is called scaffolding.
Scaffolding refers to the context provided by knowledgeable people such as adults to help children to develop their cognitive skills.
An important aspect of scaffolding is that there is a gradual withdrawal of support as the child’s knowledge and confidence increase.
A contemporary application of Vygotsky's theories is "reciprocal teaching", used to improve students' ability to learn from text. In this method, teacher and students collaborate in learning and practicing four key skills: summarizing, questioning, clarifying, and predicting.