I mainly agree, I think. Often someone seeing a person of half white/half black ethnicity will not know and will use a term based on which looks more likely, without intending to make any judgment that either term is better. OTOH, there is often no reason for a stranger to use either term. But if asked to describe someone, I would usually take a shot (assuming I am going to describe them). If I knew the parent’s races, might refer to that (again, depending on circumstance and assuming I choose to describe at all).
I wasn’t home when a census person came to our place and Jaspess I (who is black) worked with that person. But I think that person assumed that I was black too, and recorded me as such. So according to the Census Bureau, I’m black until 2030.
As one of my favorite-ever jobs, I was a professor for a few years at FAMU, a traditionally “black” college. FAMU publicized that they were not “black,” but multi-racial or multi-ethnic. There were a couple of pale faces in my classes, but anyone who saw them would have said they were black.
I wondered if FAMU’s public relations folks would’ve classified Obama as white or at least multi-ethnic.
As someone else noted, some states in the US have historically had laws decreeing that if you had more than some portion of sub-Saharan ancestry, you were “black”. In some cases, the minimum amount was “one drop of blood”.
I think a bigger piece of the puzzle is that, in the US at least, there is a certain culture and certain set of experiences common to people of certain groups. (Admittedly, that statement is overbroad and a generalization…but I’m ignoring that for the sake of making a point.) It is therefore logical that someone of mixed ancestry might identify with the portion(s) of their ancestry that they are most attached to.
My family tree and DNA are indicative of being a mutt. However, I tend to identify as Native American because the stories I remember being told as a small child and many family traditions are from that background…even though in blood-quantum terms, I’m more Scots than anything else.