Commenter Mug of Pee writes:

in the mother country, blighty, it is possible to be poor AND upper class at the same time.

it’s RARE, but it happens.

in the US it’s even rarer. it probably doesn’t exist.

but ultimately, just like aesthetics…

class doesn’t lie.

you talk. i talk. we know…

is class just money + time?

probably.

but it seems like something CONCRETE.

when you talk to people.

Social class is indeed just money + time, or perhaps occupational status + time.

It is possible to be poor and upper-class, in the same way it’s possible to be a black person who is a British citizen.

Citizenship is to wealth and occupation as race is to social class.

In other words, you don’t just become a member of the lower class just because you lose your wealth,  your lineage must live in poverty for multiple generations to be lower class.

Similarly, you don’t just become white because you immigrated to Europe, your lineage must have lived in Europe for many generations to be white.

So ultimately, social class is a biological concept to be studied by taxonomists.

We’re all animals, but the animal kingdom can be subdivided into different classes, such as mammals and reptiles.

Mammals can be subdivided into different orders, such as primates vs rodents.

Primates can be subdivided into different families such as hominids vs Cercopithecids.

Hominids can be subdivided into different genera such as Homo vs Pan.

Homos can be subdivided into different species such as modern humans vs Neanderthals.

Modern humans can be subdivided into different races such as Caucasoids vs Negroids.

Caucasoids can be subdivided into different ethnic groups such as British vs French.

And finally, the British can be subdivided into different social classes such as Upper Class vs Prole.

Of course these subdivisions are largely arbitrary, and at the narrower levels, may be much more cultural than genetic.  Perhaps, as a commenter once hinted, the only way to objectively prove them is to do a hierarchical factor analysis of all the inherited traits of everything to ever live, but such a task is beyond anyone’s capability.