Final answer:
The term used to define the type of help provided by more advanced thinkers in a culture, as proposed by Lev Vygotsky in his sociocultural theory of development, is 'scaffolding.'
Step-by-step explanation:
Lev Vygotsky, a Russian psychologist, developed the sociocultural theory of development, positing that children learn and develop cognitively through social interactions within their culture. In this framework, more knowledgeable individuals such as parents or peers provide support that helps learners develop new skills or knowledge. The term that defines this type of instructional assistance is scaffolding. Scaffolding involves the more knowledgeable guide providing structure and support to the learner, gradually reducing help as the learner becomes more proficient. This concept is akin to the physical scaffolds used in construction, which are removed once the structure is able to stand on its own.