What Are the Four Types of Hair?

Hair type and texture are determined by many factors including genetics. The four hair types are type 1 straight, type 2 wavy, type 3 curly and type 4 tight curls.

Hair type and texture are determined by several factors including genetics. Straight hair is one of the most common hair types across the world. Each person has a unique texture.

There are four main types of hair texture: Type 1 - straight, Type 2 - wavy, Type 3 - curly and Type 4 - tightly curled. The hair type and texture can be further broken down into a, b and c based on the hair's curl pattern, density, porosity, width and length. For example, someone with loose curls would be Type 3a and someone with tight curls would be Type 3b.

Types of hair and texture are as follows

• Type 1 is straight hair that doesn't curl. This hair type also has the most sheen, is the most resilient and is hard to damage. It is also immensely difficult to curl this type of hair because the scalp sebum spreads easily from the scalp to ends, making it the most oily type of hair and difficult to style.
  • 1a - Stick straight
  • 1b - Straight with more volume
  • 1c - Straight with body wave and a couple of visible S-waves, usually the neck or temples
• Type 2 is wavy hair that is in between straight and curly. The sheen is in between wavy and curly. Wavy hair is also more likely to become frizzy than straight hair. Certain types of wavy hair are easy to style, whereas others are more resistant to styling.
  • 2a - Loose, stretched S-waves
  • 2b - Shorter, more distinct S-waves
  • 2c - Distinct S-waves with some spiral curls
• Type 3 is curly hair that looks like the letter “S” or “Z.” This hair type is usually voluminous. It is highly climate-dependent and can become frizzy and get damaged easily. Proper care is required to maintain healthy, well-defined curls.
  • 3a - Big, loose spiral curls
  • 3b - Bouncy ringlets
  • 3c - Tight corkscrew curls
• Type 4 is the hair that is coiled very tightly. It is often fragile with a very high density. This type of hair shrinks when wet because it has fewer cuticle layers than other hair types. It is more susceptible to damage than other hair types.
  • 4a - Tightly coiled S-curls
  • 4b - Tightly coiled, Z pattern curls
  • 4c - Mostly Z-patterned, tightly kinked and less defined curls

Genetics and environment affect hair type and texture.

Genetics of hair type: Research shows that hair type and texture are inherited. There is also an “additive” trait contributing to hair type and texture. This means the amount of curl in the hair depends on how many curly hair gene variations are inherited. Hence, two curly-haired parents may not always have curly-haired children because many different genes are involved. Curly-haired parents can also carry straight hair genes, which they may pass on. Genes can also interact with each other to determine hair texture. This is the reason why in a family, different people may have different types of hair.

Environment: Genes aren't the only factor affecting the hair type. The environment can also have a big impact on hair, especially the texture. Humidity can make the hair frizzy or curly, whereas cold winter air can make hair dry and frizzy. Hair texture also changes with age. Hair becomes grey, thinner, rougher, finer and dry. The oil glands in the scalp shrink with age. How you treat and style your hair can change its texture. Bleaching, hair coloring, using styling tools, straightening and perming can change hair texture. 

It is not possible to change the genetics of hair. There are several at-home and salon treatments that can help straighten or curl the hair. Some of them are long-lasting, whereas others are temporary.

The following are the long-lasting treatments to change hair type

• Professional permanent perming or straightening: This is a chemical process that permanently alters the hair. It changes the protein bonds in the hair. The results can last for several years depending on the chemicals used. The new hair that grows would be of the person’s original hair type.
• At-home treatments: Several chemical kits can be used to straighten or curl the hair. Some products may provide results that last a few months, whereas others may last longer.
• Semi-permanent hair straightening: Keratin hair treatment, Brazilian blowouts and other semi-permanent hair straightening treatments can help straighten hair. They are usually done at salons. The results last three to five months.

The results typically last until the next hair wash. Temporary methods include

• Blow drying: Blow drying is done by blasting hot or cold air on the hair using a round or flat brush to curl or straighten hair.
• Using hair care products: Shampoos, conditioners, leave-in conditioning products, hair serums and hairsprays are used to coat the hair strands, reduce frizz and curls and improve hydration.
• Applying essential oils: Using natural oils such as coconut oil, almond oil, argan oil or a combination of oils can help improve hair texture. They can be applied all over the scalp and hair and washed after 30 to 60 minutes with shampoo and conditioner. This may be done multiple times a week.
• Hairstyling tools: Hairstyling tools such as hair straighteners or curlers use heated plates powered by electricity that can quickly straighten or curl hair. These are easy and quick to use.