Virtually every individual holds a unique set of social and political attitudes, affinities and preferences in a myriad of issues. These idea-elements constitute what is known as “belief systems” and they play a fundamental role in shaping our understanding, interpretation and organisation of thoughts and actions within the political sphere. The literature on political socialization acknowledges that the formation of constrained belief systems begins early in life, well before full citizenship is attained, yet the process of when and through which processes a structured set of attitudes and ideas is developed remains underexplored. Addressing this gap, the present study constitutes an exploratory effort to formally examine the development of belief systems during the formative years of adolescence. Departing from a novel sample of UK individuals aged 12 to 21, I employ the methodological tools of network psychometrics to map the web structure of political attitudes throughout the years of adolescence and early adulthood. This methodological approach allows me to model adolescents' preferences across political issues as relationally interconnected, focusing on how cognitive and social maturation transforms the structure of these belief systems. Specifically, I explore the dimensionality of belief systems, looking at how issue-preferences within the attitudinal network covary together and form stable clusters of attitudes that "go with" one another.