Philosophically, I'm a human and so are you. To some extent my identity changes based on the topic and my perception of who I am talking to, you may call me identity-fluid.
Jews can be my "cousins", because I am a Jew, Arabs can be my cousins because they're Semites, Russians can be my cousins because of my ancestry in the Soviet empire, or indeed any Soviet subject group, some more so than others...

Italian-Americans can be my cousins for their role in the development of New York City in the past, Chinese-Americans can be my cousins for their role in the development of New York today, Wisconsinites/Michiganians/Minnesotans can be my cousins because they were in large part settled by New Yorkers back in the day, the "West New England", Californians can be my cousins because they're coastal and New York played a large role in their settling over the years, even up to today, and there are others I probably can't think of at the moment.

Or I can just be a New Yorker. Or I can just be an American. I'm fairly spoiled for identity. The only identity I could want to develop is a personal and interpersonal one of my own.

But I can't be everyone's cousin in the same instance.