Curly hair comes from genetics, determined by genes like TCHH and PRSS53, which influence the oval shape of the hair follicle and how keratin distributes, causing hair to grow in a spiral rather than straight. This is often inherited as a dominant trait, but environmental factors and hormones can also temporarily change hair texture.
Curly hair is most common amongst people with African, Mediterranean and Native American ancestry. There's a specific gene that helps shape the hair shaft and determine hair texture, and it's called trichohyalin.
What race has curly hair? People of African descent typically have curly hair. Curly hair has a defined curl pattern that ranges from loose waves to tight coils. However, people of other races can also have curly hair, depending on their genetic makeup.
The rarest hair type is generally considered Type 1A, which is extremely fine, straight, and wispy, lacking any natural bends or waves, making it difficult to hold a curl but naturally sleek and prone to oiliness. While curly hair types (Type 3 & 4) are less common globally, 1A stands out as the least voluminous and textured straight hair, often seen in people of East Asian descent, though it's considered rare across all populations due to its unique fineness.
Naturally, curly hair is relatively common but varies by population and ethnicity. Globally, it's estimated that about 11% of people have naturally curly hair. The prevalence can be higher or lower in specific regions due to genetic diversity and ancestral backgrounds.
The gene for curly hair in Caucasians
It has been long established that curly hair is a dominant trait in Caucasians and straight hair is recessive.
Your biological father can pass on physical traits such as your biological sex, eye color, height, puberty timing, fat distribution, dimples, and even risk factors for certain health conditions.
Curly hair is considered a “dominant” gene trait, meaning if one of your parents had curly hair, they gave you two curly-haired genes, and you're more likely to have curls.
You're blessed with natural volume and texture
Another boon of curly hair is that, unlike others, we don't have to create volume. Our tresses always appear volumized and textured.
Asian hair is the thickest, with a larger diameter of about 70 µm. Caucasian hair has an average diameter of 65 µm, and African hair is the finest, with a diameter of 55 µm. The cross-section of Asian hair is the most round and uniform, Caucasian hair has an elliptical shape, and African hair has a flattened shape.
As we age, hormonal shifts, slower cell regeneration, and changes in the hair's internal structure (like the production of keratin and sebum) can all contribute to curls loosening, tightening, or becoming less defined. Your hair, like your skin and body, evolves with time.
Kinky hair is a uniquely human characteristic, as most mammals have straight hair, including the earliest hominids. Robbins (2012) suggests that kinky hair may have initially evolved because of an adaptive need amongst humans' early hominid ancestors for protection against the intense UV radiation of the sun in Africa.
The highest prevalence of curly hair was in Brazil (42.6%) and lowest in China (5.5%).
The Curly Hair Theory is the idea that curly hair behaves differently from straight hair because of its structure, follicle shape, and chemical bonds. It's not just a style - it's a science. Here's the science made simple: Curly hair follicles are oval or asymmetrical, which makes strands bend and spiral as they grow.
Fathers will always pass their X chromosome to their daughters and their Y chromosome to their sons.
Intelligence genes are situated on the mother's X chromosome. Thus, an intelligent mom has intelligent kids even if their fathers aren't wise. Scientists from the University of Cambridge conducted this study. The 'conditioned genes' behave differently depending on their origin.
Study shows paternal genetics dominate
The rarest hair type is generally considered Type 1A, which is extremely fine, straight, and wispy, lacking any natural bends or waves, making it difficult to hold a curl but naturally sleek and prone to oiliness. While curly hair types (Type 3 & 4) are less common globally, 1A stands out as the least voluminous and textured straight hair, often seen in people of East Asian descent, though it's considered rare across all populations due to its unique fineness.
Individuals of African ancestry, for example, are more likely to have curly hair due to the oval shape of their hair follicles. Additionally, the Keratin Associated Protein (KAP) cluster genes, responsible for the structure of keratin fibers, have been found to have variations in many African populations.
These features are largely attributed to the genetic makeup of the Indian population. The genetic code inherited from ancestors influences the shape of the hair follicles, the distribution of melanin, and the overall strength of hair shafts.
The texture of curly hair adds body and volume, creating a look that is hard to resist. Finally, men are attracted to curly hair because it is unique and eye-catching. Curly hair stands out in a crowd and can be a great conversation starter. It is also a great way to express your personality and creativity.
Red is the rarest hair color, but to understand why that's the case, you need a basic grasp of the science.
Curly hair has for centuries always been linked to individuals of Middle Eastern and African ethnicity. We find it interesting that such a generalisation can be made as there are always exceptions to every rule. Let's uncover the truth.