It's entirely possible that Mengele did group arrivals based on appearance, but I find it extremely unlikely it would have happened that way with anyone younger than 15. Remember, when Irma Menkel was asked by Anne Frank for cereal, she immediately thought "no, she's not a little kid". Meanwhile, when she learned Anne was 15, she was shocked because Anne looked more like a 12 year old. If Mengele was letting 14 year olds pass by ass 15, Anne should have been sent to the crematoria for passing by as 12.
PS: Intersocial, his is not an Anne Frank thread. I'm simply using her as an example in comparison with the Auschwitz narrative.
- - - Updated - - -
Red... I am going to invite you to watch Dario Gabbai's testimony, where he states the gas chamber capacity was 2000-2500 people, and that "there was no room for anything else but standing up". Surely Irene Zisblatt would have fit in a Birkenau gas chamber.
In response to point 1: Holy cow, so all you do is say "I'm 20", and you're safe? This is absolutely crazy, because she could have quietly passed this information to multiple others her age.
Mengele was also taking into account general health among arrivals.













