Mix raced children have more health problems

[Grimm]

Mixedrace children suffer from more health problems
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1448064/

Racemixing leads to outbreeding depression & pairings of non-complementary traits.

A massively well-funded study of over 100,000 schoolchildren found that "Adolescents who identify themselves as mixed race are at higher health and behavior risk than those of 1 race." Indeed, even when controlling for education, socioeconomic status, and other factors, there is an across-the board higher rate of health risks amongst mixed race adolescents than mono-racial adolescents.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1448064/

One study found that White-Asian mixes had a 2x higher rate of being "diagnosed with a psychological disorder, such as anxiety, depression or substance abuse."
http://www.eurekalert.org/pub_releases/2008-08/uoc--baa081108.php

A study on Black-White mixes in agreement found that "When it comes to engaging in risky/anti-social adolescent behavior, however, mixed race adolescents are stark outliers compared to both blacks and whites." This holds true despite being raised in similar environments to mono-racial children.
http://www.msu.edu/~renn/RHE-_mixed_race.pdf

Often race-deniers and cultural Marxists will bring up Haldane's rule, arguing that since races can mix and create fertile offspring, the genetic distance is not too great. Haldane's rule is "when in the offspring of two different animal races one sex is absent, rare, or sterile, that sex is the heterogametic [XY] sex."
http://www.nature.com/scitable/topicpage/haldane-s-rule-the-heterogametic-sex-1144

Indeed, although Black-White mixes are not sterile and males are not absent, males (the heterogametic sex) are more rare than females.
http://www.jstor.org/pss/1537084

The argument regarding Haldane's rule is also meaningless because different species in the animal kingdom can breed and still produce fertile offspring. The wolf (Canis lupus) and the dog (Canis lupus familiaris), the coyote (Canis latrans), and the common jackal (Canis aureus) are separate species yet can all interbreed and produce fertile offspring.
http://www.jstor.org/discover/10.2307/3671304?uid=3739600&uid=2&uid=4&uid=3739256&sid=47699085472247

Two species of orangutan (Pongo abellii from Sumatra and Pongo pygmaeus from Borneo) can interbreed despite having different chromosomal numbers.
http://www.nytimes.com/1995/02/28/science/orangutan-hybrid-bred-to-save-species-now-seen-as-pollutant.html?pagewanted=all&src=pm

The common chimpanzee (Pan troglodytes) and the bonobo (Pan paniscus) and many species of birds, such as the pintail (Anas acuta) and the mallard (Anas platyrhynchos), can interbreed as well.
http://www.sciencedaily.com/releases/2007/04/070420104723.htm
http://birdaz.com/blog/2011/02/24/mallards-the-weird-and-the-wonderful/

The gibbon and the siamang can also interbreed to produce a hybrid
http://www.ncbi.nlm.nih.gov/pubmed/451603
http://www.ncbi.nlm.nih.gov/pubmed/1060807

Some species that aren't even in the same genus can interbreed.
http://aob.oxfordjournals.org/content/74/2/111.full.pdf

Black Americans are a hybrid race of around 22% White ancestry
http://genomebiology.com/content/10/12/r141

This 22% ancestry is the cause of multiple negative health effects due to genetic incompatibility. Indeed, consistent with Haldane's rule, unmixed Blacks from Africa and White Americans do not have the same rate of birth problems that hybrid American Blacks have: "In 2005, the mortality rate for black infants was 4.4 times higher than that of white infants... African women who come to the United States and have babies experience the same low rate of infant deaths as white American mothers."
http://t1nyurl.com/6tr9e6t (docs.google)

"Indiscriminate interbreeding between distinct forms, whether 'species' or markedly different races, is not generally beneficial. The defect may show in a change in the sex-ratio of the offspring, probably caused by the early abortion of members of one sex, generally the male in the case of mammals."
http://www.amazon.com/Race-John-R-Baker/dp/0936396040

LTA4H, or "leukotriene A4 hydrolase" is found on chromosome 17. An allele of this gene increases the risk of heart attack (the #1 cause of death in America) in Blacks by more than 250%, but only 16% in Whites. The 30% of Whites with this allele have counteracting genes, while the 6% of Black Americans who obtained it through race mixing do not.
http://www.ncbi.nlm.nih.gov/pubmed/16282974

The average rate of success for mixed race couples is around half that of same race couples, 0.127 compared to 0.213.
http://www.jstor.org/stable/4145377