Half white half black hair strand

Poliosis (also called poliosis circumscripta), is the decrease or absence of melanin (or colour) in head hair, eyebrows, eyelashes or any other hairy area. It is popularly known as white forelock when it affects hair directly above the forehead.

This condition can cause single or, less commonly, multiple white patches on the hair. Some mistake these white patches for simple birth marks. In poliosis there is decreased or absent melanin in the hair bulbs of affected hair follicles; the melanocytes of the skin are usually not affected.[1]

Associated medical conditions[edit]

Poliosis occurs in several genetic syndromes such as piebaldism, Waardenburg syndrome, neurofibromatosis type I, and tuberous sclerosis.[2] It can also occur in conditions such as vitiligo, Vogt–Koyanagi–Harada disease, alopecia areata, sarcoidosis, and in association with neoplasms and some medications.[1]

It is sometimes called a Mallen streak, after a fictional family with hereditary poliosis. The Mallen family featured in a sequence of novels by Catherine Cookson, of which The Mallen Streak was the first. She later adapted them into a TV series called The Mallens.[citation needed]

During his tenure as the host of Talk Soup, host John Henson repeatedly referred to his own poliosis as a "skunk spot".[citation needed]

In DC Comics one of Batman's Robins, Jason Todd, is sometimes portrayed with a white forelock.[citation needed]

In Marvel Comics, the X-Men member Rogue has a prominent Mallen streak which is a consistent visual trademark of the character. In her earliest appearances, the character was drawn with a closed-cropped hairdo which had two small white streaks originating above her temples and reaching back over her ears to the back of her head. Over time, she came to be drawn with a larger section of white hair at her forelock, although its size varies greatly from artist to artist. This visual aspect of Rogue's appearance has been consistently portrayed in every adaptation of the character, however, in the 2000 X-Men live action film, Rogue is shown to initially have all brown hair, developing the permanent white streak after being forced to absorb a significant amount of power from Magneto.[citation needed]

The characters Percy Jackson and Annabeth Chase each develop a white streak in their hair from the strain of holding up the sky in The Titan's Curse, the third novel in the book series Percy Jackson and the Olympians.[citation needed]

Cruella De Vil is thought of to have this condition with her half-black/half-white hair.[citation needed]

The main character Jio Fleed of the Satan 666 manga series seems to have the condition.[citation needed]

During his Christmas special, Jeff Dunham was doing a bit with Achmed the Dead Terrorist and mistakenly combined scoliosis with polio, making poliosis.[citation needed]

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 islinkedto 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.

What is biracial hair?

Half white half black hair strand
Share on PinterestEddie 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.

Researchersoften usethe 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 resultsshow 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.

Hair types

Share on PinterestInfographic 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 typeShapeType 1: Straight• 1a: very straight, fine, or thin texture
• 1b: straight with some bends
• 1c: straight with a coarser textureType 2: Wavy• 2a: wavy and fine
• 2b: wavy with a slightly more defined S-shape
• 2c: wavy with well-defined S-shaped wavesType 3: Curly• 3a: loose curls
• 3b: tight and springy curls
• 3c: an “S” or “Z” shape that springs back into shape when stretchedType 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.

Biracial hair cells

A strand of hair has three maincomponents:

  • 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.

How genetics play a role

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.

Astudyin 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.

Caring for biracial hair

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.

Summary

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.

Why is my hair strand half black half white?

If your natural hair color is brown/black, then it normally has a specific amount of dark vs light pigment. The middle section of this hair is grey because there was an absence of melanin production when the hair was still growing.

Why is one of my hair strands half white?

Share on Pinterest Poliosis causes white patches of hair. The white hair caused by poliosis is due to a lack of a pigment called melanin in the hair follicles. The condition is usually associated with the hair of the head. It can affect any hairy area of the body, however, including the eyebrows and eyelashes.

Why is one strand of hair multiple colors?

The tone of the hair is dependent on the ratio of black or brown eumelanin to yellow or red pheomelanin. Levels of melanin can vary over time causing a person's hair color to change, and it is possible to have hair follicles of more than one color on the same person.

Why are some hairs black and some white?

Melanin is the same stuff that makes our skin's color fair or darker. It also helps determine whether a person will burn or tan in the sun. The dark or light color of someone's hair depends on how much melanin each hair has. As we get older, the pigment cells in our hair follicles gradually die.