Genetic factors play a significant role in determining people’s hair type. A combination of different heritages can result in varied hair types that range from straight to wavy or curly to coiled or kinky.

A person’s hair is linked to their genes. Genetic factors can influence the texture and thickness of their hair and the shape and size of their hair follicles.

Hair types can vary among different populations. A biracial individual, who has parents of different races, can inherit characteristics of two types of hair, which can lead to a variety of hair types and different curl patterns.

This article discusses what biracial hair is, how genetics affects hair type, and how to care for different kinds of hair.

A child with curly hair. Biracial hair often has a mixture of textures.Share on Pinterest
Eddie Pearson/Stocksy

A wide variety of hair textures can appear in people of dual heritage. In some cases, people have multiple curl patterns. One study even showed that it is not uncommon for a person to have both straight and very curly hair.

Researchers often use the terms European hair and Caucasian hair interchangeably to refer to straight or wavy hair. They typically consider East Asian hair to be very straight and use African or “afro” to describe curly, kinky, or coily hair.

However, these terms are inherently flawed. Many people of European and Asian descent have curly hair, and curl patterns vary greatly among people of African descent. As the combining of ethnicities becomes more common in an increasingly global world, these historical ways of describing hair may become increasingly less accurate.

Genotyping results show that 94.9% of Black people have curly hair. Additionally, 12.7% of Europeans and 12% of Asian people have curls.

Biracial hair is a complicated term, and it does not refer specifically to one hair type or shape. It can be straight, wavy, kinky, curly, or coiled, or a combination of some or all of these types.

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Infographic by Diego Sabogal

It is difficult to classify biracial hair accurately, as many people’s hair is a combination of different textures.

In hair styling, a hair typing system categorizes hair curl patterns from one, which is straight, to four, which is coiled. Each category has subclassifications — A to C — which are based on the diameter of the wave, curl, or coil.

Hairstylists use the following categorization system:

Hair typeShape
Type 1: Straight• 1a: very straight, fine, or thin texture
• 1b: straight with some bends
• 1c: straight with a coarser texture
Type 2: Wavy• 2a: wavy and fine
• 2b: wavy with a slightly more defined S-shape
• 2c: wavy with well-defined S-shaped waves
Type 3: Curly• 3a: loose curls
• 3b: tight and springy curls
• 3c: an “S” or “Z” shape that springs back into shape when stretched
Type 4: Coily• 4a: loose coils
• 4b: zigzagging coils
• 4c: tight coils

As biracial hair is so unique, people may have hair of different curl patterns and thicknesses, meaning that they have several of these hair types.

Although there is very limited research on biracial hair, a 2019 study found that in an analysis of hair strands from a diverse set of women who identified as biracial, the coily strands were nearly always thicker than the wavy strands. The researchers also noted that having several interspersed textures can cause tangles and breakage.

Learn more about hair types and textures.

A strand of hair has three main components:

  • the medulla, which is the core
  • the cortex, which surrounds the medulla
  • the cuticle, a thin layer of scales covering the medulla

Although experts do not completely understand how hair curls, the cortex is likely to have the most significant effect on curl pattern.

The cortex contains cortical cells, of which there are three different types. Each type has a different arrangement of keratin filaments — a protein also present in the nails. Experts think that the different types of cortical cells determine a strand’s curl pattern.

Genetics plays a major role in determining hair texture. A hair’s curl pattern, thickness, and texture are all linked to a person’s genes.

Studies suggest that different genes may influence hair texture and thickness in people of different ethnicities. For example, research has shown that the FGFR2 and EDAR genes influence hair thickness in Asian populations.

A study in South Africa found that many different genetic factors contribute to hair type and that the KRT74, TCHH, and CUTC genes all play a role in determining the curl pattern.

It is likely that many genes contribute to the thickness and texture of hair across populations, and researchers are just starting to understand which genes cause different hair types to occur.

The best haircare approach varies depending on a person’s hair texture and type. However, for the many biracial people who have a combination of hair types, caring for the hair can be slightly more complicated.

A person may wish to focus on reducing breakage. A 2019 study on biracial hair found that the surface of the hair often showed severe damage at the roots.

This is likely a result of different hair types and thicknesses working against each other and becoming tangled.

A person may find it beneficial to determine their curl type or types, as well as their hair thickness and porosity. Porosity refers to how well the hair can hold moisture.

Once they have an idea of what kind of hair they have, the person can follow specific guidelines to care for it. Some general recommendations are:

Curl type

Wavy hair, or hair that curls loosely, is usually easy to keep moisturized. People can use moisture sprays or lotions, which are flexible and light.

For curls and tight coils, people may need to use light products with a milky consistency and concentrate them at the ends of the hair. This treatment should help keep the hair hydrated and tangle-free.

Tighter curls can easily become dehydrated. For kinky and tightly coiled strands of hair, people may wish to apply thick and buttery moisturizing products on a regular basis. They may also find that their hair retains moisture better if they wash it less often.

Porosity

Low porosity hair does not retain much moisture. As a result, it is less likely to tangle or frizz, so a person can use lightweight moisturizing products.

High porosity hair can lose moisture quickly, so it may require thicker, creamier products.

Thickness

Thin hair is less likely to get frizzy than thick hair. However, it may break easily, so people with thick hair may benefit from using more moisturizing products.

Biracial hair does not refer to one particular texture or type of hair — rather, it can be incredibly varied. Research has shown that many biracial people have a combination of different hair types and textures.

Genetics plays a major role in hair type, but experts still do not understand exactly which genes cause hair to behave differently across populations.

People can determine what type of curl pattern they have by using a classification system that ranges from one to four. Once they know what kind of hair they have, they can choose the right products and methods to care for it.