My theory as to its origin is that America was settled by the landless masses of Europe, and that they came here to break the monopoly on land ownership held by European aristocracies. In America, land was free and widely available, all you had to do was steal it from the Indians and import slaves to work it.

However, once the settlers got here, they found that all the good land was already taken by earlier waves of immigrants, and they were forced to go deeper and deeper into the wild and dangerous interior to get their share. The earlier waves were already established, had all the land suitable for plantation agriculture (the real moneymaker!) and had aped the refined and cultured lifestyle of European aristocrats. The new, poor settlers WANTED to live like aristocrats, but they hated and envied them too, and the big landowners, merchants, manufacturers and professionals in the colonies (the "gentlemen of property" we now like to call "the founding fathers") hated the white trash newcomers and saw them as uncouth, social-climbing, johnny-come-lately rabble. Even if they made it through hard work and sheer grit, the old landed gentry just saw the new ones as nouveau riches In other words, we had invented our own new aristocracy,one based on wealth and education instead of inherited nobility.

Plebeian America developed a hatred of intellectuals and education, unless it was associated with land and money (business). It is considered fine to be clever when it comes to business, or street smarts, or sports, but not in those areas that were associated with the upper crust. So it became easy to hate education and refinement as affectation and snobbery, but of course, social climbers are not likely to treat the accumulation of wealth and power with the same righteous and democratic disdain.

This did not stop our own aristocrats from being progressive and intellectual by the standards of their time, the ruling classes of colonial America were remarkable and formidable men: scholars, soldiers, lawmakers, planters, busnissmen, merchants and more. They combined intellectual achievement with practical acumen; men of action and men of letters. Even the decadent intelligentsia of 18th century Europe admired and grudgingly respected our Franklins and our Jeffersons and our Washingtons. But our common citizens always saw them as just "uppity". (There's that word again.)

It lasts to this day, it is not considered socially acceptable to be smart, and certainly not to display it openly if you are. The poor, and even the not-so-poor, flaunted their "just plain folks" ideal in a variety of ways, including adopting manners of speech and accents that disguised whatever economic success or education they might have achieved otherwise. This attitude is present to some extent throughout the New World, but for some reason became most prominent in the British colonies later to be associated as the United States, particularly those colonies most suited for plantation agriculture.

I should make clear that this anti-intellectualism, this casting of all intelligence and education as conceited, treasonous, effeminate, and cowardly has nothing to do with our blood or genes or race. It is purely cultural, the result of social and historical forces operating blindly in the background. It is just a perfect storm of random influences, that, of course, has been maliciously exploited and magnified by unscrupulous political and economic interests. Americans are no dumber or smarter than anyone else in the world, but they act really stupid in public, as if they were ashamed of whatever culture and refinement they might have.

Yeah, maybe you haven't noticed it, just as fish don't notice the water they swim in. But I've noticed it. And my family and acquaintances in my immigrant community certainly noticed it and remarked on it at length. It forms a big part of our stereotype of "American", and like all stereotypes, it is exaggerated and unfair, but there is a kernel of truth to it.