Lev Vygotsky produced a theory of cognitive development that emphasises the important role that cultural forces play in development. He argued that human history consists of the development of new ‘cultural tools’ for dealing with the world. By ‘cultural tools’ he meant new ways of co-operating, organising, planning, communicating and calculating, which then determine people’s thinking. Vygotsky believed that cognitive development is influenced by biological maturation and the child’s interactions with others.