It's probably genetic to be honest. I mean, if all the members in a family had the same personality, they would all want the same things and probably end up falling out with each other. If we all have different preferences and want different things, then it avoids conflicts, so, in this respect, it's innate. But our personality is also affected by the life experiences we have. If one brother has a traumatic experience that his sister doesn't have, then this will have an effect on his personality and possibly change it.
正直なところ、遺伝的な要素があると思います。家族全員が同じ性格だったら、みんなが同じことを望み、お互いに軋轢が生まれてしまうかもしれません。異なる好みや欲求があることで、衝突を避けることができるため、この点では生まれつきのものだと言えるでしょう。しかし、私たちの性格は、経験によっても影響を受けます。一方の兄が持つトラウマ経験が姉にはない場合、彼の性格に影響を与え、変える可能性があります。