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Straight Hair or Curly Hair, Which is Dominant? Explain Why?

According to reports, 45% of individuals have straight hair, and 15% have curly hair in the US. In this article, we will know which one is dominant and why.

Which One is Dominant and Which One is Recessive?

Curly hair is dominant and straight hair is recessive. That’s why if a child is born from parents of both curly and straight hair, the dominant curly hair will be inherited by the child.

Curly and Straight Hair Concerning Ethnicity

Curly hair is known as African hair.

African hair originates from the African continent. This type of hair is characterized by tight curls, twists, and kinks. This hair has moderate density and a low growth rate. 

Straight hair, also known as Caucasian or Asian hair, originates from the western and Asian regions.

Straight or wavy strands characterize this type of hair. They have the highest density and a faster growth rate.

What Determines Hair Traits?

Most of what you will look like comes from the combination of your parents’ genes.

Which also includes the texture and color of your hair. The genetic information present in your body creates a blueprint for what your hair is going to look like.

There are also other factors, like nutrition, health conditions, and hormones, which will likely have less impact than your gene.

What is the Dominant and Recessive Trait?

The genetic code that determines what you look like is called alleles. Our parents deliver us with two alleles. In total, we have four alleles.

There are two types of alleles, namely dominant and recessive.

 The dominant allele is the one that overpowers the recessive allele in terms of trait or appearance.

Even if we have an equal number of dominant and recessive alleles, the dominant alleles will always override the recessive ones in terms of expressing traits.

Now we will know why is curly hair a dominant trait

There are two types of alleles: one is dominant, and the other one is recessive.

The curly hair alleles are dominant. That is why someone with four alleles, two dominant (Curly) and two recessive (Straight) alleles, will have curly hair.

The reason is that the alleles for curly hair are dominant. The dominant allele overpowers the recessive allele. Even if there are equally dominant and recessive alleles, the dominant alleles will appear as the characteristics over the recessive alleles.

Since the alleles that code for curly hair are the dominant allele so curly hair is dominant.

Now let us know why straight hair is a recessive trait

The alleles that determine straight hair are recessive.

As we know by now from the above discussions, dominant genes will always overpower recessive genes in terms of expressing traits. That is the reason why straight hair is not a dominant trait.

If one of your parents gave you a pair of curly alleles and another gave you a pair of recessive alleles, you will carry the recessive genes, but it will never be expressed as your trait.

Thus straight hair is considered a recessive trait.

What Hair Trait will a Child of Both Curly and Straight Hair Parents Have?

From the above discussion, it is clear that the child will be born with curly hair since curly hair is dominant and straight hair is recessive.

And we all know by now that if the dominant allele is present, it will override the recessive allele while expressing the trait.

But there is a possibility that the child will be born with straight or wavy hair.

Now the question is how?

For example, the child’s father has curly hair, and the mother has straight hair.

For example, the child’s father has curly hair, and the mother has straight hair. So, the mother will provide the child with two sets of recessives (straight) alleles.

But the father might give the child a dominant (curly) allele and a recessive (straight) allele since the father can have curly hair as he has a dominant allele.

So, now the child will have one dominant allele and three recessive alleles. In this case, the child will bear straight hair.

Hair Care Routine Differences of Curly and Straight Hair

Curly and straight hair have different shaped follicles and formation and implantation to the scalp, so their care differs significantly. They each have their various needs. 

Some of the everyday cares are –

  • Use sulfate-free shampoo but in the case of straight hair, use it in your scalp and hair. But for curly hair, restrict your shampoo use to your scalp as it removes the essential oil.
  • Wash curly hair every week, but wash straight hair 2-3 days a week.
  • Use conditioner lightly for straight hair, but use conditioner more than shampoo in curly hair.
  • Apply conditioner only to the shaft and avoid the roots for straight hair, but deep-condition up to the roots for curly hair.

You can’t Control Your Genes

You might be born with dominant curly hair or with recessive straight hair. But this is totally out of control. Use appropriate hair care routine and proper styles for your hair type to elevate your looks.

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