In 1970, estimates from the United States Census indicated that there were only 500,000 multiracial individuals living in the United States. By 1990, this number had increased to nearly 2 million.21
In the 2000 census, 2.4% of the population, roughly equivalent to 6.8 million people, were identified as multiracial.22
Multiracial individuals will continue to factor more prominently into the demographics of the United States as a whole.8
Based on current estimates, by the year 2050, 21% of the United States population will identify with multiple races.23
Although groupings of DNA sequences called Single Nucleotide Polymorphisms (SNPs) hold some eventual promise of objectively quantifying race,24–26
data on both race and ethnicity are most accurately obtained using self-identification. In addition, it is important for categories to be meaningful to the outcome in question and to the respondents in the sample.27
In Hawai‘i, it is practical to differentiate Native Hawaiians from other Pacific Islanders because of factors that have historically affected this indigenous group. Other groups such as Micronesians are small in number in terms of overall population. While they could be easily incorporated in the Pacific Islander category, in some instances it is important to consider this group separately as they are uniquely affected by recent emigration status, infectious disease burden, and exposure to ionizing radiation from US nuclear weapons testing.28
The categories of race and ethnicity defined by the US Office of Management and Budget usually do not adequately reflect the multiethnic and multiracial population in Hawai‘i. Thus, medical and public health researchers have utilized different methodologies in an attempt to more accurately delineate race and ethnicity in this group. One technique involves providing individuals with a comprehensive list of race and ethnicity choices as well as a “refused” and “don't know” category. In one question, individuals are allowed to select all of the races and ethnicities that apply to them. Individuals with multiple races and ethnicities can thereby select more than one race or ethnicity. In a second question, individuals are asked to select the race or ethnicity that they most identify with. Depending on the medical or public health question being studied, different analysis can draw on what is most meaningful to the particular outcome.
US Census data shows that allowing multiracial individuals to select more than one race can result in marked differences in the resulting statistics. In the 1990 census, when individuals were allowed to select only a single race, census data showed there were nearly 2 million American Indians living in the United States. In 2000, when respondents were allowed to select more than one race, 4.2 million individuals reported they were either American Indian alone or in combination with another race. This corresponded to an increase of 110 percent.29
A similar increase was seen for Native Hawaiians. In 1990, approximately 139,000 individuals living in Hawai‘i were Native Hawaiian. In 2000, there were 282,000 people reporting that they were Native Hawaiian alone or in combination with another race.30,31
The Hawai‘i Health Survey, a continuous statewide household survey conducted by the Department of Health, uses a similar though slightly different approach to race and ethnicity.32,33
Respondents are given a list of races and ethnicities and can select four categories from a list of 20 (including refused, “I don't know,” and other) for their mother and their father. This results in up to eight indicators of ethnicity for the respondent. Multiethnic, multiracial respondents are then assigned to a single ethnic category by means of an algorithm determined by the Office of Health Status Monitoring. Specifically, if Native Hawaiian is listed as an ethnicity for either the mother or father, the individual is categorized as Native Hawaiian. Otherwise, the person is considered to be the first non-Caucasian ethnicity listed for the father. If the first listed ethnicity for the father is Caucasian or unknown then the individual is considered to be the first non-Caucasian ethnicity listed for the mother. Use of this algorithm increased reporting in the Native Hawaiian group. Statistics derived from this technique are considered more accurate measures of the overall number of Native Hawaiians living in Hawai‘i. For example, a larger number of Native Hawaiians were reported in the Hawai‘i Health Survey than in the 1990 census. However, one can see the shortcomings of using an algorithm rather than self-identification as it assumes the importance of ethnicity for multiethnic and multiracial individuals.
In the “blend methodology”, which has also been used in Hawai‘i, the ethnicity of the individual is determined by ascertaining the ethnicity of the individual's parents and grandparents and deriving a percentage.34
For individuals with many different races or ethnicities, asking about a specific person in their family, may initiate more detailed thinking about race and ethnicity. In the blend methodology, ethnicity can be used as a categorical or as a continuous variable in which the proportion of a given ethnicity is incorporated into the analysis. Using a similar methodology, our group ascertained that of nearly 6,000 babies born at a medical center in Hawai‘i between 2007 and 2010, 11.6% had 5 or more racial or ethnic groups.35
In terms of the multiracial, multiethnic group, there are many unanswered questions. Are there common or shared experiences for multiracial or multiethnic individuals beyond living in a relatively mono-racial society? While the psychiatric literature historically described a kind of “double rejection” among multiracial individuals which included disapproval from both communities,36,37
it is unclear whether these experiences still apply or whether this will change as the United States becomes more diverse. In recent studies, the multiethnic, multiracial group was identified as having different prevalence of various health outcomes that range from diabetes to low birth weight.38, 39
A study from 1996 showed that individuals who were full Native Hawaiian had more than double the age-standardized mortality as part Native Hawaiians.40
Many social and societal factors can influence how multiethnic, multiracial individuals identify their own race and ethnicity. Studies have demonstrated that multiracial and multiethnic individuals tend to report fewer races and ethnicities as they get older.41
The boundaries of race and ethnicity can also depend on how questions are asked, the context in which they are being asked, and how the answer will be used. Situational ethnicity refers to identifying with a particular ethnicity within specific contexts.42
Factors that can influence what an individual identifies with include where one lives and the perceived loss or benefit that could result from one's answer. The acceptance or denial of a certain culture, belief system, religion, or even a particular family member as well as phenotypic appearance can also play a role in self-identification.
Additionally, individuals may not know their racial or ethnic background. Individuals may be multiracial but may not report it because they do not know about a detailed family history from generations past. This is especially true in places like the United States which has a history of institutionalized racism. Literature from the 1930s includes descriptions of Native Hawaiians as “indolent,” “in need of constant supervision,” and “deceptive”.43
This is believed to have prompted many individuals to report they were a different race rather than suffer discrimination.
In Hawai‘i, certain groups, particularly those that are smaller in overall number such as the Native Hawaiian group, are commonly multiracial and multiethnic. A study done by the Office of Hawaiian Affairs estimated in 1984 that of the 200,000 Native Hawaiians living in Hawai‘i, 8,000 had a “100% Hawaiian blood quantum.”44
As the indigenous race, however, there is substantial cultural awareness and many Native Hawaiians may primarily identify with this ethnicity when asked. Thus, in the 2000 Census, more than 80,000 individuals reported themselves as only Native Hawaiian.30
With this type of cultural identification, that could play a role in lifestyle and health care outcomes, it is typically more useful to group multiracial individuals who are part Native Hawaiian in the Native Hawaiian category than in an overarching multiracial category.