Humans have the capacity to continue to develop intelligence. Vygotsky differentiated between our higher and lower mental functions. In contrast, our higher mental functions develop through social interaction, being socially or culturally mediated. Behavioral options are limited when functioning occurs at an elementary level. Without the learning that occurs as a result of social interaction, without self-awareness or the use of signs and symbols that allow us to think in more complex ways, we would remain slaves to the situation, responding directly to the environment.
Mediation occurs through the use of tools or signs of a culture.
Language and symbolism are used initially to. When the cultural artifacts become internalized humans acquire the capacity for higher order thinking. Learning is a constructivist activity. Cognitive development is a process in which language is a crucial tool for determining how the child will learn how to think because advanced modes of thought are transmitted to the child by means of words. Prior to mastering his own behavior, the child begins to master his surroundings with the help of speech.