It used to be only Western European cultures were taught specifically & the rest of the world was divided into regions with 1 or 2 example listed for each:
Southeastern Woodlands-Cherokee, Creek
Sub-Saharan Africa-Chad, Congo
To depict people as "primitive" use habitat terms...

To depict people as less primitive they use geographic terms
Northern Africa, South-East Asia etc
Now that Asians aren't depicted as primitive Asia is taught as individual nations, same with Eastern Europe
Teachers don't say "now it's time to learn some racism" instead...

...racism is normalized across the curriculum
Chances are, early on most noticed the subtle manipulations that lead many otherwise rational adults to think of the Indigenous of Africa & the Americas as mono-cultures & chances are those who spoke up were treated as trouble makers

Racism hurts Euro-Americans too, holding completely irrational beliefs not only makes you look foolish far more often than you know, you're also MUCH easier to manipulate by those in power
When you don't realize North America's biggest city is larger than 3 European countries...

..it's easier to believe Europe deserves more gold/silver/oil (that came from the Americas) than countries in this hemisphere
When you don't know that the state of Georgia is twice the size of the nation of Georgia it's easier to believe Americans use more resources

Racism wasn't invented to manipulate people already in shackles & legally defined as wildlife; racism was invented to manipulate oppressed European settlers & that's not conjecture, because few of them read at that time their overlords felt safe to say so in print & it's archived