Why are older sisters so mean?

because like they know their older they start to boss u around n say bad stuff.Like my big sister she says things to me but in spanish like pee face n stupid and more.N like she don't know inglesh much i say bad thing in front of her when she says stuff to me and the reason of them being so mean n rude is cause,they think their all that cause when little kids want to do some thing the parent say just to give it to them n they get mad so they be mean n ruff with the little ones that's why...