This whole argument is bullshit. The environment shapes human beings, NO SHIT. It still doesn't mean that every human is as strongly affected by this shaping, and if you really believe there are no cases that don't seem to be shaped very much at all, you should probably visit different parts of town once in a while.
You are right about the statistic stuff.
But even what you call almost not at all shaped is heavily shaped. Sure people may not hold the views upheld as normative by the "leading fraction" of their peers/state/culture. But when growing up people take up a set of core believes and habits, pattern recognition and problem solving, etc. (*) that - assuming that they have an internal logic - will shape what they believe. There's also statistically some who do differ to others here, but they either become institutionalized or great mathematicians. Sometimes both.
That is what is meant with shaped - I assume you understood it more directly (on of those cultural habits is, unfortunately, never to clarify statements with several meanings in an argument). Still that doesn't mean "everything" or that we could make silly laws about culture -> action, but outright denying that you are influenced makes you look like you are unable to reflect about those things.
(*) Arguably a lot of that is genetically hardwired or something. Still makes little difference - you are still influenced by your parents.
