This whole argument that race might not have biological foundations, but people believe it does, therefore it is real, reminds me of an old asylum joke:
A person was committed to a mental hospital because he believed he was a mouse. After a prolonged therapy, the shrinks managed to cure the guy and, consequently, decided to release him. On the day he was supposed to leave the hospital, the doctor who treated him shows up to say goodbye and wish him good luck. As they talk in the hallway, a cat runs by. The patient is absolutely terrified. "What's wrong?" asks the nonplussed doctor. The patient points at the cat. "My friend" says the doctor "but you've been through the therapy, and now you know you are not a mouse." "That's true, doc" replies the patient, "I know that I'm not a mouse. But does the cat know that too?"
wojtek