Hi there! Have you ever wondered why some people have straight hair while others have curly hair? Let’s dive into this fascinating topic and find out what makes our hair the way it is!
Did you know that whether your hair is straight or curly is mostly determined by your genes? A study from 2009 found that the likelihood of having wavy or curly hair is about 85 to 95 percent based on genetics. This means if your parents have curly hair, there’s a good chance you will too. The same goes for straight hair. If one parent has curly hair and the other has straight hair, you might end up with wavy hair.
So, how do these genes actually make your hair curly or straight? It all comes down to something called hair follicles. These are tiny organs under your skin that produce hair. The shape of the follicle affects the shape of the hair that grows out of it. People with curly hair have asymmetrical follicles, which produce oval-shaped hair that curls. On the other hand, people with straight hair have symmetrical follicles that produce round hair.
Interestingly, the genes that affect hair texture can vary among different populations. For example, Asian people are generally less likely to have curly hair compared to African people, with Europeans somewhere in between. According to the Genetics Science Learning Center at the University of Utah, straight hair in Asians is influenced by different genes than those affecting hair texture in Europeans and Africans.
Some people experience changes in their hair texture over time, like going from curly to straight or vice versa. Scientists aren’t entirely sure why this happens, but it might involve changes in the hair follicle itself or the use of hair styling tools. One theory suggests that a cell surface receptor called the epidermal growth factor receptor (EGFR) might play a role in altering hair growth.
And there you have it! The mystery of why hair is straight or curly is mostly down to genetics and the shape of your hair follicles. Isn’t science amazing?
If you have any more big questions, feel free to ask. Keep exploring and learning!
Conduct a survey among your classmates to find out their hair types and their parents’ hair types. Analyze the data to see if there is a pattern that supports the idea that hair texture is inherited. Create a chart to present your findings.
Create a 3D model of a hair follicle using clay or other craft materials. Make two versions: one for straight hair and one for curly hair. Explain how the shape of the follicle affects the hair texture.
Research the prevalence of different hair textures in various populations around the world. Create a map or infographic that shows the distribution of straight, wavy, and curly hair globally. Discuss how genetics play a role in these differences.
Conduct an experiment to see how water affects different hair textures. Wet strands of straight, wavy, and curly hair (you can use wigs or extensions) and observe any changes. Record your observations and discuss why these changes might occur.
Interview a local hair stylist about how they work with different hair textures. Ask them about techniques and tools used to change hair texture temporarily. Share your findings with the class and discuss how science and art come together in hairstyling.
Sure! Here’s a sanitized version of the transcript:
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Hi, I’m Craig. I have naturally long, flowing hair. This balding is cosmetic, and this is a Mental Floss video. Today, I’m going to answer Clarabelle X’s big question: What makes hair naturally straight or curly? Let’s get started!
According to a study conducted in 2009, wavy and curly hair have a heritability of around 85 to 95 percent. Basically, if a person has curly hair, it’s very likely that their child will have curly hair too. The environment plays a role as well, but a much smaller one. So if both your parents pass along a curly hair gene, you’ll probably have curly hair. The same goes for straight hair; if both have it, then so will you. If one passes down a curly hair gene and the other passes down a straight hair gene, then you’ll likely have wavy hair.
But how do these genetics make hair appear a certain way? They actually affect the follicle level. A hair follicle is a tiny organ below the skin that produces hair, and for hair to grow, it has to be forced through a tube whose shape affects the hair. People with curly hair have asymmetrical follicles, which grow oval hair that curls. Their hair also tends to grow at a sharp angle. People with straight hair have symmetrical follicles with round hair rather than oval.
These genes actually vary from population to population. You may have observed that typically, Asians are less likely to have curly hair than Africans, and Europeans fall somewhere in the middle. According to the Genetics Science Learning Center at the University of Utah, straight hair in Asians is mostly caused by variations in two genes, which are different from the ones that influence hair texture in Europeans. Different genetic variations make hair curly in African and European populations.
There are some people whose hair changes from curly to straight or the other way around, though experts haven’t figured out how this is possible. It probably means that the follicle itself has changed, or they used a hair straightener. Some believe that it happens thanks to a cell surface receptor known as the epidermal growth factor receptor (EGFR), which can grow outside of the follicle and potentially change how hair grows.
Thanks for watching this Mental Floss video! If you have a big question of your own that you’d like answered, leave it below in the comments. See you next week!
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Let me know if you need any further modifications!
Genetics – The study of heredity and the variation of inherited characteristics in living organisms. – Scientists use genetics to understand how traits like eye color are passed from parents to children.
Hair – A filamentous biomaterial that grows from follicles found in the dermis, or skin, of humans and other animals. – The study of hair can reveal information about a person’s health and diet.
Follicles – Small secretory cavities, sacs, or glands in the skin from which hair grows. – Each hair on your head grows from its own follicle.
Curly – Having a spiral or coiled shape, often used to describe hair texture. – Curly hair is often the result of the shape of the hair follicle and genetic factors.
Straight – Having no curls or waves, often used to describe hair texture. – People with straight hair have round hair follicles, which affect the way their hair grows.
Populations – Groups of individuals of the same species living in a specific area. – Scientists study populations of animals to understand their behaviors and how they interact with their environment.
Texture – The feel, appearance, or consistency of a surface or substance, often used to describe hair or skin. – The texture of hair can be smooth, coarse, or somewhere in between, depending on genetic factors.
Receptors – Protein molecules that receive and respond to chemical signals in the body. – Receptors on nerve cells help us detect sensations like touch and temperature.
Science – The systematic study of the structure and behavior of the physical and natural world through observation and experiment. – Science helps us understand how the world works, from the smallest cells to the largest galaxies.
Growth – The process of increasing in physical size or developing over time. – The growth of plants depends on factors like sunlight, water, and nutrients from the soil.
