In some sense, this article could be really racist, if someone believe this is just another scientific racism crap. But hey, I'm also attacking my own race, because I'm ( chance) not a multiracial being1.
People who belong to a single race are result of a very board inbreeding.
Inbreeding product offspring with higher chance of having
* reduced fertility both in litter size and sperm viability
* increased genetic disorders
* fluctuating facial asymmetry
* lower birth rate
* higher infant mortality
* slower growth rate
* smaller adult size
* loss of immune system function.
[Quoted from the Wikipedia article: Inbreeding]
Of course, this is a very board inbreeding, it's possible every marriage of one's parent, grandparents and so on are kept between nth cousins, when n is a positive integer larger than 6. That's only possible, because I don't have enough data to do statistic operations on them, but it's likely somewhere along the line, there are going to be very close inbreeding. But that's not the point, multiracials have ancestors does inbreeding too. Except they are experiencing less degree of inbreeding by being multiracial.
Let's define superiority as more adopt to natural selection, which most humans in developed countries does not experience. In some socialites (like US), there are laws protect the weak.
Single racial people have less genetic diversity than multiracial. It's true, because single racial people's gene pool are restricted to one race, compare to multiracial with 2 or more. Larger gene pool means high chance to adopt catastrophic changes. Just hypothetically speaking, there are 2 race of some space aliens, Alpha and Beta, if Beta are immune to a deadly and very contagious disease D-A because their genetic trait, in the same time Alpha is immune to D-B. Then it's possible that 2 disease will eventually kill all of those 2 race. Even if only one survives, the other race's gene pool (Like the gene allow fast body regeneration) can never be accessed, and that's a lose to it's entire species. Suppose, the Alpha and Beta chose to mix with the other, they will product offspring with immunity to both. (Because each gene could suppress the other, they can actually only product offspring immune to non of the disease, that would be too bad.) Both gene pools will be preserved.
In the human world, the above will not happen, at least not in our lifetime, I never heard of "Asians does not get AIDS". But it's proven that multiracial people have great traits helps them physically. [Wow, I actually learned something from AP Bio]
How many multiracial people are there in US? I don't know, but I can name some famous ones: Tiger Woods, Halle Berry, Kristin Kreuk and Keanu Reeves. Seems like multiracial people can be great at what they do.
Come on, the entire world should start promote the greatness of having multiracial children. Maybe it's just me, if I ever want to have kids, I want multiracial ones.

Ok, ok, everything I just said is just excuses, I started this topic because there was a topic in Gene Expressions about multiracial women's attractiveness.
The multiracial girls I have seen is generally more attractive than single racial ones. In percentage, 100% of the multiracial people I met in real life can be considered as attractive(my opinion), same not true for single racial ones. Beauty is in the eyes of the beholder, it differs from person to person, but there are the standard deviation, and I believe I'm in the ±1 range.
Here are some of the famous interracial girls I found attractive, and if most of you find them attractive, my point is proven.
Leah Dizon [Chinese+Filipino+French]

Maria Ozawa [Japanese+French-Canadian]

Tina Yuzuki/Rio Carnival [Japanese+Portuguese]

Two of them are AV idols, but hey, how can they not be noticed if their picture are shown in every large portal site in China (which at least prove most Chinese people found them attractive).
I don't know if multiracial guys are hotter than usual ones, if any girl who read my blog, please comment about it.
The main reason multiracial girls are hotter might be because the law of physics. When 2 people from different race mix, it creates entropy. The world are spontaneously moving toward higher entropy(by making guys attract to multiracial girls), unless there is energy used to prevent it from happening. The population of human race are increasing, more and more energy is needed to counteract the entropy, eventually, everyone will be multiracial, because unlike most chemical reactions, this one is irreversible.

A dialog between me and a person who claims he is multiracial, judge it for yourself.

*one~神~龍~Mino~夜神優斗: in this society
*one~神~龍~Mino~夜神優斗: MR are having advantages
*one~神~龍~Mino~夜神優斗: why?
*one~神~龍~Mino~夜神優斗: they can speak more then one language
*one~神~龍~Mino~夜神優斗: and
*one~神~龍~Mino~夜神優斗: they are having outstanding looks
*one~神~龍~Mino~夜神優斗: plus
*one~神~龍~Mino~夜神優斗: they are usually rich
*one~神~龍~Mino~夜神優斗: as for MR men
*one~神~龍~Mino~夜神優斗: they can have a nice job easier
*one~神~龍~Mino~夜神優斗: and they can attract more women
Mgccl: ...do you have any fact support that?
*one~神~龍~Mino~夜神優斗: yes
*one~神~龍~Mino~夜神優斗: cuz i am already one MR= =
Mgccl: ..
Mgccl: fuck no...

1. 1. My aunt says I'm 25% Jewish, but Jewish is not even a race, it's people belong to a religion.