Icelanders are extremely inbred. That, and their detailed genealogical records, make them an extremely valuable resource for genetic study. However, their life expectancy is quite high, probably more in correlation with their lifestyles than the detrimental effects of inbreeding.

Humans as a whole are fairly inbred. "Mitochondrial Eve" only lived about 150,000 years ago, making us perhaps one of the most genetically homogenous species on the planet. And when you're genetically homogenous already, you don't notice the effects of inbreeding that much.
valich said:
Those of African descent normally breed with others of African descent, while whites or caucasians usually only breed with other whites, and Asians breed with Asians. When whites breed with blacks, the offspring grow up being called bananas or melanoes and they don't know where to fit in.

the only reason people have a problem with being 1/2 & 1/2, is because many people are too racist. Being 1/4, 1/4, 1/4 & 1/4 hasn't hurt Tiger Woods, or his chances with cute Swedish girls, see below:
And then Tiger Woods said he wasn't actually "black" at all -- he was "Cablinasian."
Woods made his remarks on "Oprah," when he was asked if it bothered him to be called an African-American. "It does," he said. "Growing up, I came up with this name: I'm a 'Cablinasian.'" As in Caucasian-black-Indian-Asian. Woods has a black father (or to be precise, if I am interpreting Woods' reported ancestry correctly, a half-black, one-quarter American Indian, one-quarter white father) and a Thai mother (or, with the same caveat, a half-Thai, half-Chinese mother).
BARBADOS, West Indies -- Tiger Woods married his Swedish girlfriend Elin Nordegren at a ceremony on the Caribbean island of Barbados, local media reported

actually, we're all Africans; whites, Asians, blacks we all evolved from Adam & Eve, check below:
Population geneticist Dr. Spencer Wells, an explorer-in-residence at the National Geographic Society, is director of the project.
"Genetics, I think, resoundingly has answered the question of where we ultimately came from, we came out of Africa. And we came out quite recently, within the last 50 or 60 thousand years," Wells said.
Did I say I say I was prejudice? Makes me wish I was Tiger Woods!

Thanks for elaborating his ethic diversity. Really, I never had a clue!

Your last citation makes me wonder how long in geological history (millions of years) that it takes for a species to diverge into another species so that they are no longer able to interbreed?