A fundamental premise of Vygotsky's therefore, is that tools and signs are first and foremost shared between individuals in society and only then can they be internalized by individuals developing in the society as is reflected in this famous quote: "Every 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).
وبالتالي فإن الفرضية الرئيسية لفيجوتسكي هي أن الأدوات والعلامات يشترك فيهما أولاً وقبل كل شيء الأفراد في المجتمع ويمكن استيعابهما فقط من قِبل الأفراد الذين يتطورون في المجتمع كما يتجلى في هذا الاقتباس الشهير: «"Every 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).