According to which theorist ‘cultural tools’ play an important role in…

In developmental psychology, 'cultural tools' refers to the signs, symbols, language, and technologies that a society provides to a child, which mediate and shape the way the child thinks, remembers, and solves problems. This idea forms the foundation of the sociocultural theory of cognitive development.

Lev Vygotsky is the theorist who developed sociocultural theory. He argued that a child's cognitive development is not purely an internal, individual process but is shaped through interaction with cultural tools and with more knowledgeable members of society — an idea he formalized through the concept of the Zone of Proximal Development, the gap between what a child can accomplish alone and what they can accomplish with guided support. (The related idea of 'scaffolding' was later developed by Wood, Bruner, and Ross, building on Vygotsky's work.)

• Jean Piaget's stage theory explains cognitive development as a sequence of universal stages (sensorimotor, preoperational, concrete operational, formal operational) built through a child's own interaction with the physical world, with a limited role for cultural mediation.

• Albert Bandura's social learning theory explains development through observation and imitation of models, formalized through concepts such as self-efficacy, rather than through cultural tools.

• B.F. Skinner's behaviorist framework explains behavior through external reinforcement and punishment schedules, without reference to internally mediated cognitive processes.

Therefore, Lev Vygotsky is the theorist according to whom cultural tools play an important role in the cognitive development of children.