This wouldn’t surprise me at all, tbh. My uncle (first son) is way taller than my dad (second son) because back in the day my family didn’t have much money, and they prioritized feeding the oldest son. Same genetics, different childhood diet. Uncle is like 6’2", my dad is like 5’6". If there had been a girl sibling involved, she probably would have gotten even less food.
This wouldn’t surprise me at all, tbh. My uncle (first son) is way taller than my dad (second son) because back in the day my family didn’t have much money, and they prioritized feeding the oldest son. Same genetics, different childhood diet. Uncle is like 6’2", my dad is like 5’6". If there had been a girl sibling involved, she probably would have gotten even less food.