" It is common to assume that multi-racialism is inevitable, and that racial identity will disappear as races mix. Americans prefer to think that the “tragic mulatto,” welcome in neither community, was either a myth or a reflection of outmoded racist thinking. Research suggests things may not be so simple.
A 2003 study of 90,000 middle-school and high-school students found that black/white mixed-race children had more health and psychological problems than children who were either black or white. They were more likely to be depressed, sleep badly, skip school, smoke, drink, consider suicide, and have sex. White/Asian children showed similar symptoms. The principal author concluded that the cause was “the struggle with identity formation, leading to lack of self-esteem, social isolation and problems of family dynamics in biracial households.”
The authors of a 2008 study reached the same conclusion: “When it comes to engaging in risky/anti-social adolescent behavior, however, mixed race adolescents are stark outliers compared to both blacks and whites. . . . Mixed race adolescents—not having a natural peer group—need to engage in more risky behaviors to be accepted.”
A study of white/Asian children found that they were twice as likely as mono-racial children—34 percent vs. 17 percent—to suffer from psychological disorders such as anxiety, depression or drug abuse.
Yoonsun Choi of the University of Chicago found that in Seattle middle schools, a clear racial identity seemed to protect against certain problems. Bi-racial children were the group most likely to smoke, take drugs, have been in fights, hurt someone badly, or carry a gun. Prof. Choi believes mixed-race children suffer because no racial group accepts them. “There is some indication that a strong ethnic identity helps protect kids from these [undesirable] behaviors,” she said. "

― Jared Taylor , White Identity: Racial Consciousness in the 21st Century