How did the Nazis figure out whether a person or community is 'Aryan' or not?

If the Nazis wanted someone to be “Aryan”, they made up some cock and Bull story to justify it. If they wanted the opposite, they could be equally inventive in assigning someone to “Untermensch” status.

And then we get sexy time with them!

And then we get sexy time with them?

Trump is going to target known criminals in the country illegally for deportation. The Democrats have vowed to fight him every step of the way. Don't they understand this is one of the issues that cost them the white house, the house and senate?

It was all bullshit the Nazis made up as they went along. Trying to cast it in real scientific terms is a waste of time.

Poles are “ugly, subhuman Slavs” but hey, Hermann, have you noticed how hot and blond those leggy Polish chicks look? They don’t fit our “subhuman” model at all! İn fact, they kind of look like our Aryan ideal personified!

Ja, well, Helmut, it’s very simple. Those hot leggy blondes are actually not Slavs at all but are, in fact, Aryans who got Slavicised. We need to rescue them from the pit of subhumanism that surrounds them by immediately giving them Aryan status!

Inside the Spectacular Downfall of UnitedHealth and Its CEO - WSJ

Ultimately, what made a group of people “Aryan” or not came down to how much they wanted them to be “Aryan”.

Nazi racism was not actually scientific, it was just a load of bullshit with a thin patina of “science-y” garwharbl to justify what was basically a totally ideological belief.

They used their “spidey sense”.

Why are leftist movements so popular among young people?