What children can do with the assistance of others might be in some sense even more indicative of their mental development than what they can do alone
Lev S. VygotskyThe true direction of the development of thinking is not from the individual to the social, but from the social to the individual.
Lev S. VygotskyEvery function in the child's cultural development appears twice: first, on the social level, and later, on the individual level; first, between people (interpsychological) and then inside the child (intrapsychological). This applies equally to voluntary attention, to logical memory, and to the formation of concepts. All the higher functions originate as actual relationships between individuals.
Lev S. VygotskyChildhood is a complex dialectical process characterized by periodicity, unevenness in the development of different functions, metamorphosis or qualitative transformation of one form into another, intertwining of external and internal factors, and adaptive processes which overcome impediments that the child encounters.
Lev S. Vygotsky