Well, I can understand wanting to be thicker, but I'd certainly be happy with the length. True story coming up, though: I used a flexible jelly dildo as part of a strap-on, on my partner recently, to try to give her vaginal & cervical orgasms (she's had them in the past with VWE boyfriends, but has only had clitoral with me). She was very wet, but said she felt absolutely no difference - girth or length - between me & the dildo. Size difference: the dildo was 7.25x5.5. I find that quite incredible, but I have a feeling it was because she was so wet & does have a deep vagina.
As for race differentials in size: I believe in them personally, but I can see how they could be damaging. The only ones who stand to win from such 'stereotypes' are Asians, reputedly smaller on average. I can understand why African-Americans who are 'mainstream average' (whatever that is) may feel the pressure to be as big as they're 'supposed' to be.
But as I'm not A-A, or Asian, I can't talk with any credibility about their circumstances. It's all just conjecture.