Were the survivors the originals or their tethered counterparts?

Question

Ok, so while it is clearly explained in Jordan Peele's Us (2019) that Adelaide got switched with her tethered counterpart as a child, what about her children? Were they weird just because they were technically half tethered, born to a human father and formerly tethered mom? I guess since the real Adelaide (Red) was stuck with the tethered all those years and forced to have babies with the tethered version of Adelaide's husband, those underground tethered kids were technically half tethered / half human too.

Above ground daughter is Zora, tethered daughter is Umbrae. Was the Zora we see at the end of the movie the same Zora we saw at the beginning of the movie and was she the same Zora that was originally born above ground to Adelaide & Gabe? Please think about the whole discussion of her track abilities and then how poorly she ran when trying to get away from Umbrae.

Above ground son is Jason, tethered son is Pluto. Both these kids were strange, Pluto of course more so, but same question...Is Jason the same kid throughout the movie and has he always lived above ground or was he maybe at some point switched with his tethered version? Points to consider...making the sand castle tunnels, the short disappearance on the beach, understanding the tethered so much quicker than everyone else, making his double walk into the fire, the burns on his double possibly preventing speech.

Answer 1

All the shadows / clones / tethered people / underground people couldn't talk. We see this throughout the movie, when they're attacking the original humans. They groan. They roar. They scream. The only one that can talk is Red (Lupita Nyongo), and that's because she was actually a human, swapped with her mute clone as a child. That mute clone was then taught to talk over time.

At the end of the movie, everyone in the SUV was a human (except the odd case of Red / Adelaide). We know they're humans because they've all talked recently.

Answer 2

Just want to add, the movie seems to strongly suggest that the Tethered are human.
Red also mentions it during her final confrontation with Adelaide.

What defines the Tethered, is the conditions in which they happen to have been born - or raised.
Their limited access to resources, or level of education (that we, people from the Surface, would think is low or even nil), gives them no other choice but develop these characteristics (difficulty to communicate verbally, a tendency for violent expression? - yet when cultivated, an ability to efficiently overthrow whole regions of the Surface overnight).

The story of Adelaide shows it: even if you were born Tethered, you can have chances to integrate the Surface society.

The fact that the Tethered are human, feels to me as a parallel with the arbitrary of our societies: where and how you were born (something that you cannot control), decides what you can and cannot become later in your life.

Remember also the dialogue about a potential athlete career at the beginning of the movie, Adelaide tells her daughter she can become whatever she wants if she wills it. It might be a hint how Adelaide and her family integrated the privileges and freedoms of living Above.

So there are no strict rules about being a Tethered, one can join the Surface society with a lot of luck.
Now there are no clues in the movies that Adelaide family had the same experience as her, and we can only imagine that they have only ever known life above the Surface.