That's an interesting premise, do you think that the heads of e.g. the KGB were representative of the majority of Soviets? It was my impression that there was a large class distinction between the Soviet intelligence apparatus and the proverbial average Joe.
Note: I selected the USSR/KGB not for any particular resemblance to current Western intelligence agencies (much more human intelligence and shotgun mics back then) but rather because they seem to me to be the textbook case of the effects of mass, pervasive surveillance over a long time.
To give a growth hacking analogy, becoming KGB head is the final step in the funnel. To be a KGB head you should probably have qualities that 99.99% of the people do not posses. But it is wrong to say he does not represent the majority of soviets because the entry to the system and almost every other step in the funnel is highly biased towards those who conform to majority opinion.
For example when I say Donald Trump is representative of majority of conservative base I do not mean majority of conservative base is narcissist and billionaire. I basically mean Trump is pro-Gun, pro-Life, pro-Christian, anti-Gay. Because without those criteria he would not have entered the funnel in first place.
Conservatives or Liberals the current trend among American politicians is "trust us", "bend before authority", I am 100% sure no person can rise to top in American government if he does not conform to these ideas.
I haven't studied the period, but my impression was that it was very much possible for a brilliant person from humble origins to rise to the top on the basis of their skills. Though becoming outright head would probably require networking/corruption as in any large organization.
Note: I selected the USSR/KGB not for any particular resemblance to current Western intelligence agencies (much more human intelligence and shotgun mics back then) but rather because they seem to me to be the textbook case of the effects of mass, pervasive surveillance over a long time.