Is there a such thing as Acting A (Insert Race here) ? Options

[IAmBackMuaha]

I hear many people around saying negative comments to other people like, "Your acting white when you're black. Your acting black." ... Those are common things to hear and I've been wondering, is there really a such thing as acting a certain race? And we can all (Or most of us) assume that what those people mean by "Oh your acting white, your acting black" is a person doing a lot of activities, or dressing up, or being good at a certain thing many people of a certain race outside of his or her race would do. To me it's sickening and has never understood it. Many asians excel in Math and Art. So if a White, Black, or a Hispanic person excels in and truly loves both areas, I know it would be stupid and unacceptable to say, "He or she is acting Asian. Many african-americans excel in Basketball. If I am white, and basketball is all I play, all I really love in this world, it's my passion, I'm acting black? Hm. I've never particularly understood about dressing like a certain race, which is the biggest question mark out of all others. We as humans can dress like however we want as long as we are not naked. But I know in certain races, we're used to seeing people of different races dressing similarly. People make stereotypes, white - Abercrombie, Hollister. black - any clothing associated with "hip-hop". Stereotypes exist but I wish such stupidity didn't. Please enlighten me if you can and explain on how a such thing as "acting like a certain race" exists.