America performed plenty of unusual experiments too. Between MK Ultra, the gay bomb, and the Tuskegee syphilis experiment, and that's only counting ones the government was directly involved in, I'd say we gave the Soviet Union a run for their money when it comes to mad science. It was the cold war, each side was looking for something game changing to one up the other.

What they were trying to do/prove would depend a lot on which experiment specifically you're looking at, I'd think. Plus it'd maybe be good to keep in mind that scientists in the west were getting up to some strange stuff during the Cold War as well. science in general involves a lot of poking around at things in ways that look really nonsensical until they produce usable results, which there's no guarantee whatsoever that any given line of inquiry will. The trouble is that there's no way of knowing what'll be useful ahead of time, you have to do the legwork

Anyway, to get any kind of useful answer you're gonna need to narrow your question down drastically. What experiments are you talking about specifically? Why are they unusual. Do you have any reason to think they were trying to prove anything, in the ideological sense I think you're asking about?