How Is Race Socially Constructed

I strongly believe that race is a socially constructed and disagree with the theory that race is a natural phenomenon. Yes, different races have different physical features, but these physical differences have no affect on the actions, beliefs, thoughts, and etc. of a person. It all comes down to the mind and every person no matter what race they are born overall with the same biological make up of the brain. People can argue that this statement is false and that some races have smarter brains than others and they maybe right but the question is how did the brains of these smarter people come to be. It all comes down to social construction. For example, people may argue that white americans have a larger mental capacity than black americans and that this is a biological. I would not disagree but I would also argue that the only reason why these biological differences exhist is because of social construction.
Since the very beginning of our nations time whites ruled supreme over blacks and handled everything that required the process of thought. Over the years these white people have bred and passed down their family trees the advances they made with their brains. Blacks were unable to receive education and were forced to perform physical labor, and people wonder why blacks dominate most of the sports in the United States and are on average much more physically powerful than whites. Personally I have noticed that almost all of my black friends have a lot more muscle naturally than any of my white friends. The blacks who were forced upon physical labor passed downed their physical genes like the whites passed down their mental genes, all due to social