Try explaining this old-time conception of "black" to a foreigner, for example. That person will say, "But he's part white, and he grew up in a great neighborhood."

You respond, "But there's no intermediate category. He's black, period."

"Why?" asks the person from Japan or Bosnia.

"Because that's how whites will see him," you answer -- and deep down, you know you're arguing from another time based on things you've heard other people say. "You're either black or white, period." What?

The creakiness in this logic is one of two reasons the idea has to go that the Troys out there must "identify as black." One is that for black people to get angry at people like Woods for calling themselves something other than black means enforcing the old "one drop" rule as vigilantly as whites used to do. It doesn't matter if we do it for different reasons -- it comes out the same. Mariah Carey and Malcolm Gladwell are black just like Vivica Fox and Spike Lee, case closed? George Wallace would have been pleased.

The second reason is even sadder. The idea that if, say, a Troy doesn't "know what color he is," then he is to be giggled about at best and jumped on at worst is about shame. Why, after all, does someone who refuses to identify as black make some black people angry? Why would it matter so much to them?

That anger comes from insult -- specifically, a sense that Troy must think he's better than they are. After all, why couldn't they just allow that Troy has had a different life from theirs? Or, more simply, open up to the obvious fact that some people are genetically (and culturally) more black than others?

Those would be perfectly natural responses. Thinking that Troy looks down on you is just one alternative. And that alternative can feel natural only to someone who deep down does feel that being black is somehow lowly.

Troy, under this analysis, is pretending that he isn't down in the mud with the rest of us. Yes, the person must be thinking of blackness as mud -- because otherwise, again, why the insult if Troy refuses to join in? If you think of blackness as a privilege or a party, then you see Troy as missing out. You're not mad at him. Why would you be?

That tongue clucking and anger at the Tiger Woodses among us is about insecurity, a legacy of slavery and Jim Crow. To really know that black is beautiful means feeling not the slightest mental pinprick when café au lait people refuse to call themselves only "black" -- and to be unable to even dream of telling them that they're supposed to identify as black because of what happened to Rodney King.

There will be actual black people. There will also be those who are only part black, and there will be more of them by the decade. It's high time that America, black and white, stopped telling them that there's some kind of higher wisdom in adopting the racial-classification strategies of Strom Thurmond.

Go on, "biracial" people. I call it "black to reality."

John McWhorter is a frequent contributor to The Root.

Like The Root on Facebook. Follow us on Twitter.