In Vygotsky's theory, which aspect of development gets neglected?

Lev Vygotsky', a Soviet psychologist, has propounded the "Socio-cultural Theory". This theory implies the idea that social interaction plays a crucial role in the development of a learner's cognitive ability. 

Key Points

•  Vygotsky's theory of cognitive development focuses on the role of social interaction and culture in learning.
• Vygotsky neglects the biological aspect of development altogether.
• The other three aspects of development, social, linguistic, and cultural, are all emphasized in Vygotsky's theory.
• He believed that children learn through social interaction with more knowledgeable others, that language is a powerful tool for learning, and that culture provides the context for learning.

Thus, it is concluded that In Vygotsky's theory Biological aspect of development gets neglected.