Interesting fact which is depressing

Wow that's certainly interesting. Same with pets. We had baby chickens that would act like they can't do shit because they had us picking them up and carrying them around and feeding them. They were conditioned to just run around aimlessly after us until we fed them and pet them or sang them to sleep.
Then one day we had to travel for a bit. That week my dad's friend took care of them. When we came back from the trip, they had suddenly become such responsible little chickens, had grown dramatically, and we had to buy a new cage for them that weekend. 😶 woah.

Bring development factors have a lot of different items for instance my daughter didn't start talking until she was close to 3 most of that was due to the fact that we were in a bilingual household. She started walking at 8 months old. And people carrying around the child all the time almost any child psychiatrist and doctor would say that's bad.

That's not necessarily the only factors

Sounds like different modes of parenting rather than favoritism, unless you were both raised by the same two people. You’re also two different people and might’ve developed at different rates regardless. 🤔

You don’t understand child development my friend.