I defer to Baroness Margaret Thatcher

That is extremely unfortunate, and also quite foolish of you, considering that you know she was a baroness, meaning that her ideology reflected her (as opposed to your) class interests. Why would you care what she thinks?

Anyway, I am a social science major with an emphasis on psychology. Her hyperindividualist, simplistic take here flies in the face of the available evidence. Human societies are indeed organized, complex, dialectical systems that are more than the mere sum of their parts. Rather than behavior emanating solely from endogenous biological factors, virtually all psychological outcomes (including "personal responsibility") are instead rooted in particular social, cultural, political, and economic (environmental) factors, all of which are beyond the power of any singular individual to alter at their will. Differential life outcomes are due to variations in social experience, which draw their specific features from culture; outcomes are not due to genes, hormones, or some other intrinsic property (e.g., a "soul"). Human psychology is fundamentally cultural, abides by a thoroughly social logic, and functions to support cultural systems.

Keep in mind that all theories about human society/behavior are inherently political. The reason Thatcher promulgated these views was to mislead the masses into thinking that the social problems of the day (namely, socioeconomic inequality) were resultant of individual defects rather than the system she enormously benefited from at their expense. All conservative politics in modern society, which is rife with widespread economic and general social inequality, fulfills this function of diverting attention away from the true (social) causes of human problems and staving off progressive reform or revolution.

Regarding pedophilia specifically, are you suggesting that its violent prohibition, which takes both formal and informal forms, does not actually exist? Is it your belief that any adult can safely have sex with underage girls without facing severe social sanctions? I am perplexed as to what point you are trying to make.