what are the main reasons for a conflict between a sister and brother?

I am the middle child and have two brothers, one older and one younger and the arguments have really always been with my older brother over little things, he would get mad if I do not look for things that he lost or just about anything. It is just normal between us now to fight over little things he always picks a fight with me.

I am very close with my brother but not with my sister. My sister is my rival since we were younger. My rival in my parents attention, school grades, and even status in the company.

before when we are younger, I always fight/argue with my sister with almost everything, but now we are not arguing anymore, I can't say that we're close because we don't share stuffs with each other. I think one of the reasons why siblings argue or fight is envy.

I don't remember an instance fighting with my brother... but I guess the little fight we had would be the instances where my brother are so messy with their stuff and so lazy doing household chores... It's kind of like culturally like that here in the Philippines, where the women do most of chores.. I really hate that norm.. Everyone should do their share in the chores!!!!