First of all, inferiority complex is dated psychojargon of the 1930's, as well as freudian childhood trauma analysis.
Even if america is a melting pot, americans are certainly much more alike with each other, than with most europians, sharing a common political structure and power mechanisms, a common historical past, and as far as same classes go, same material conditions. That's enought to categorise an average middle class american by and and large, and although nitwit is admittedly kinda harsh, i think most people would agree that this average middle class american is largely misinformed and not very knowledgeable when it comes to politics, history, culture, cuisine, art, etc. etc. to name a few, compared to the average middle class europian. I mean no Europian would boycott french fries, thinking they actually were french, not knowing that potatoes actually originated from America, lol.