I think the more you must guard your words, the things you say, watch how you act, and the more you grow up with this as a child?

The more restrictive your thoughts may be as an adult. The less 'free wheeling', and therefore, more locked into tight, controlled paths.

Further to that, even if the above is not significantly true, there is still the entire "does the work I want to do, the research, threaten PRC dogma in any way?"

And worse...

"Will the work I do, threaten PRC dogma in the future."

On top of all of that, a reduction of international collaboration with others in the field, and so on.

Of course, I could be entirely wrong. But I do think that "restrictive environment" leads to "less creative output", at least in visible output.