The main problem with characteristics of Eastern European people as a whole is that there is no unifying characteristic (too bad that Fantomowe ciało króla by Jan Sowa is only in Polish, he addressed that point in that book). Estonians and Bulgarians are completely different. If we limit ourselves to Warsaw Pact countries (and not republics of former USSR) then the differences are still huge. Some countries had gradual move towards authoritarian state (from totalitarian), while others had totalitarian rule all the time. The only thing which comes to my mind as characteristic for Eastern Europe is the process of communist takeover after 1945, which went similarly in majority of then-future Warsaw Pact.