Honestly that’s with a lot of older Somali siblings, when they’re parentified because the parent constantly says “I’m tired and old I can’t raise this child anymore” like who told you to have a baby at 42?! 
I think sometimes depending on the age gap the sibling can turn abusive because of frustration with the parent, ptsd from their upbringing, and sometimes just because they want a punching bag.
I remember one time my brother asked me if I hit his daughter (my neice), I never hit them violently I only just do a small pat on the hand that doesn’t hurt AT ALL but they usually get emotional about it cause they know their being punished.
Anyway I guess he found out and asked me. I just told him “yes I did” and he asked “why would you do that” and I told him “you used to hit me ten times harder, why is it an issue when it’s your kids” and he stopped the conversation right there and went into his room
They love to put hands on you but god forbid you even pinch their child lol

I think sometimes depending on the age gap the sibling can turn abusive because of frustration with the parent, ptsd from their upbringing, and sometimes just because they want a punching bag.
I remember one time my brother asked me if I hit his daughter (my neice), I never hit them violently I only just do a small pat on the hand that doesn’t hurt AT ALL but they usually get emotional about it cause they know their being punished.
Anyway I guess he found out and asked me. I just told him “yes I did” and he asked “why would you do that” and I told him “you used to hit me ten times harder, why is it an issue when it’s your kids” and he stopped the conversation right there and went into his room

They love to put hands on you but god forbid you even pinch their child lol