Final answer:
Pierre Bourdieu is the sociologist who extended the insights of Marx and Weber, emphasizing the significance of cultural and social capital in addition to economic capital.
Step-by-step explanation:
The individual in question who extends the insights of early social thinkers such as Marx and Weber, focusing particularly on the concepts of cultural and social capital, is French sociologist Pierre Bourdieu. Bourdieu's work is renowned for its analysis of the various forms of capital that individuals and groups accumulate and how these forms of capital impact social life. His theory highlights that cultural capital (such as educational credentials) and social capital (such as networks and connections) can be as significant as economic capital in determining an individual's social position.