Underestimated by size

As a skinny girl I have had to deal with big girls trying to intimidate and walk all over me. I am not frightened by size or weight, and I have no problem confronting individuals who disrespect or offend me. I always have to defend or prove my emotional and physical strength so these big girls can cool it. I wondered why do people try to use the size to control others. These are several obvious reasons for this, but the one that is most often overlooked is hidden insecurities these individuals suffer. I have notice patterns in this type of behavior of big vs. little, big people during confrontation use all these extra communication "accessories" like they have to jump in your face, use the screaming voice level, overall high volume and try to be condescending. Why is all this necessary? There is no need for people to be acting crazy like this, yelling and screaming recklessly in your face, unless their dealing with some emotional problems. I feel these people get energy and confidence off of making others feel scared and insufficient.But what type of stable confidence can derive from an insecurity. None. Moreover when they meet an individual like me who refuses to let them use their weight to shut me down and control my actions, they squander like rodents. They feel defeated, powerless and uncomfortable by those who are not scared. I am just sick and tired of this nonsense that because your big you can beat up someone, it has clearly been proven that weight is not a determining factor in who will win a fight. I urge skinny and any other oppressed groups to continue to stand up for themselves because if you don't, you will be definitely taken advantage of.