Height is an interesting attribute that varies across human populations. Historically, there have been perceptions that certain racial or ethnic groups tend to be taller on average than others. But what do the data actually show about differences in height between racial groups in the United States?
There are a few key factors that contribute to differences in average height across human populations:
- Genetics – There are certain genetic factors that influence height such as the growth hormone receptor gene.
- Nutrition – Access to adequate nutrition, especially during childhood and adolescence, plays a major role in determining adult height.
- Socioeconomic status – Factors like poverty and access to healthcare also impact height.
- Geography/climate – Populations living in colder climates with abundance of food tend to be taller.
When looking at racial groups, genetics and geographical ancestry are important determinants of average height. But social and economic factors also play a role in influencing height within a population. To best analyze differences in height between racial groups, we need high quality data that accounts for key variables like age, gender, nutrition, and socioeconomic status.
National Health and Nutrition Examination Survey (NHANES)
One of the best sources of data on height broken down by race and ethnicity in the US is the National Health and Nutrition Examination Survey (NHANES) conducted by the CDC. This is a nationally representative survey that combines interviews, physical exams, and laboratory tests.
The NHANES data for height includes measured heights for each survey participant rather than relying on self-reported values. It also collects extensive demographic, socioeconomic, and health data. This allows us to analyze height differences between racial groups while controlling for factors like gender, income, and nutrition.
NHANES Racial Categories
The NHANES data divides the US population into the following major racial groups:
- Non-Hispanic White
- Non-Hispanic Black
- Hispanic (any race)
- Non-Hispanic Asian
These broad racial categories encompass diverse populations, but still provide useful insights into average differences between groups living in the US.
NHANES Height Data Methodology
The height measurements collected by NHANES are taken by trained health technicians using standardized procedures and equipment. This ensures high accuracy and consistency of the data.
Participants stand with their backs against a stadiometer with their shoes removed, feet together, and head positioned in the Frankfort horizontal plane. Height is precisely measured in centimeters.
The most recent NHANES survey data comes from 2015-2016. It includes measured height data on 8,174 males and 8,707 females of all ages and racial groups. This large nationally representative sample allows us to estimate average heights for each racial category with a high degree of confidence.
Average Height by Race and Gender in the US
So what story does the NHANES height data actually tell us? Are certain racial groups in the US really taller on average?
The table below summarizes the average heights for US adults ages 20 years and over by race/ethnicity and gender based on the 2015-2016 NHANES data:
| Race/Ethnicity | Average Height (cm) | Average Height (feet/inches) |
|---|---|---|
| Non-Hispanic White Males | 178.4 | 5′ 10″ |
| Non-Hispanic White Females | 163.1 | 5′ 4″ |
| Non-Hispanic Black Males | 176.4 | 5′ 9″ |
| Non-Hispanic Black Females | 162.9 | 5′ 4″ |
| Hispanic Males | 171.0 | 5′ 7″ |
| Hispanic Females | 159.4 | 5′ 3″ |
| Non-Hispanic Asian Males | 171.5 | 5′ 7″ |
| Non-Hispanic Asian Females | 157.9 | 5′ 2″ |
Based on this data, we can see some clear patterns in average heights between races:
- Non-Hispanic white males are the tallest group, averaging 5’10”.
- Non-Hispanic white and black females are tied as the tallest females at 5’4″.
- Hispanic individuals of both genders have the lowest average heights.
- Asian adults are shorter on average than whites and blacks.
- Across all race/ethnicities, adult males are around 5 to 6 inches taller than females.
Key Demographic Controls
The NHANES survey methodology is rigorous about collecting detailed demographic, health, and socioeconomic information about each respondent. This allows us to dig deeper in analyzing the height differences between racial/ethnic groups.
By controlling for factors like age, income, education level, and nutrition, we can isolate the impact of race/ethnicity alone on average height.
For example, the height gap between white and Asian adults shrinks substantially after controlling for immigration status. Second generation Asians are much closer in height to whites, likely due to nutrition and socioeconomic factors growing up in the US.
Why Do Height Differences Exist Between Races?
Now that we’ve established which racial groups are taller on average in the US, the next question is why these population-level differences exist. What factors contribute to the observed disparities in height across races?
Genetic Differences
One element is underlying genetic differences between racial populations. The distributions of certain height-related genes vary between race/ethnicity. Genes related to growth hormone in particular have been shown to differ across ancestral populations and contribute slightly to height gaps.
For example, a genetic variant of the growth hormone receptor gene called GHRd3 is more prevalent in whites and has been linked to increased height. It likely originated from a mutation thousands of years ago within European populations.
But while genetics play some small role, most anthropologists and biologists emphasize that environmental and socioeconomic factors are far more important in explaining average racial height differences.
Nutrition
Nutrition, especially during childhood and adolescence, is a huge determinant of how genes for height potential get expressed. Populations that have historically had access to better nutrition unsurprisingly tend to be taller.
The average heights of white, black, and Asian Americans today are all much taller than the average heights from their original ancestral countries. This likely reflects better access to nutrition, healthcare, and reduced poverty in the US.
Within the US, there are still disparities in childhood nutrition between races related to socioeconomic status. Hispanic and Asian children experience more food insecurity and this contributes to shorter average heights as adults.
Socioeconomic Status
Closely tied to nutrition is socioeconomic status. Poverty rates vary significantly between racial/ethnic groups and this affects access to food, healthcare, and healthy childhood environments.
Controlling for parental income and education level explains a substantial portion of height differences between white, black, and Hispanic Americans. Asian Americans who grow up in higher socioeconomic status families are taller on average.
Urban vs Rural Environments
Geography and population density also correlate with height. People, regardless of ethnicity, tend to be shorter in rural areas than urban areas. This is true both across and within countries as rural childhood environments tend to have lower incomes and worse nutrition.
The gap between rural and urban heights can be up to 5cm and partially explains variation between races if groups have different urbanization rates.
Conclusion
Based on the most recent measured height data from NHANES, non-Hispanic white males are indeed the tallest race/ethnicity/gender combination among US adults. White and black females share the title for tallest female group. Hispanics have the lowest average adult heights for both males and females.
However, these population-level differences are primarily explained by social determinants like nutrition, socioeconomic status, and geography rather than genetics. While genes do play a small role, the evidence clearly points to environmental factors as the main drivers affecting average height between racial groups.
Efforts to address childhood nutrition, healthcare access, education, and economic opportunity could help reduce height disparities related to race/ethnicity. But there will likely always be minor average differences between populations given the range of genetic variation across ancestral groups.