Why One Head of Hair Can Have Three Different Curl Patterns

CURL SCIENCE / TEXTURE

Tighter curls underneath, looser pieces at the crown and one section that seems to have its own agenda? Mixed curl patterns are far more normal than a single hair-type label makes them look.

Somewhere along the way, curly hair got the idea that it was supposed to choose one pattern and commit.

You take a quiz. Compare your hair to a chart. Decide which little curl drawing looks most like yours. Then wash your hair and discover one section making loose S-waves, another producing perfect spirals and an entire patch near your neck curling like it received completely different instructions.

That does not mean you classified your hair incorrectly.

The tidy categories are the artificial part.

Human hair exists along an enormous spectrum of shapes and curvatures, and the individual fibres growing from one scalp are not manufactured as a perfectly matched set. Researchers studying hair morphology have repeatedly found substantial variation in characteristics such as curvature, diameter and cross-sectional shape.

So having two, three or more visible curl patterns on one head is not your hair failing to fit a type. It is your hair being much more biologically interesting than the chart.

 

Every curl begins with its own follicle

Your natural curl does not begin when the strand exits your scalp and encounters a styling product. Much of its shape is being established while the fibre is formed inside the follicle.

Research examining curly follicles has found that their structure can be curved and asymmetric, including differences in the follicle bulb and the way cells proliferate and differentiate on opposite sides. When curly follicles were grown in culture, the fibres they produced retained their curvature.

Later work examining hair across a range from straight to tightly curled has connected curl formation with asymmetry within the developing fibre itself, including differences in cortical organization and keratin distribution.

That means each follicle is essentially producing its own fibre.

Your thousands of scalp follicles share your genetics and biological environment, but they are not one giant follicle taking a single curl-pattern instruction and photocopying it thousands of times.

Small differences between follicles and fibres can translate into visible differences once all of those strands grow long enough to form a hairstyle.

 

Even people with similar hair do not grow identical fibres

One of the most useful things hair research has done in recent years is move away from treating enormous populations as though everyone within them has essentially the same hair.

A worldwide study of 1,442 people from 18 countries measured hair based on physical characteristics rather than ethnicity and found enough continuous variation to develop eight broad curl categories. Later reviews have pointed out that even those systems remain simplifications of substantial human diversity.

Research involving more than 2,300 twins and siblings has also measured both hair curvature and diameter while explicitly examining variation within individuals. Genetics explained a substantial portion of average curvature, but the very design of the research reflects an important reality: the hairs belonging to one person are not assumed to be physically identical.

More recent microscopy work has gone even further, analyzing hundreds of fibres within individual hair samples because looking at only a handful of strands can miss the amount of variation present.

Which brings us back to your bathroom mirror.

If one side produces a slightly wider curl and your nape makes tighter spirals, you do not necessarily have a problem that needs correcting.

You have a population of individual fibres growing on one scalp.

 

Hair typing makes everything look much tidier than biology does

Hair-type charts can be useful shorthand. If someone tells you they have very loose waves versus very tight curls, you immediately have some information about the shapes they are describing.

The trouble starts when the category becomes an instruction manual.

Scientific researchers have developed objective systems based on measurements such as curl diameter, wave number and curvature because describing hair shape visually is surprisingly difficult to standardize. Even then, reviews have questioned how reproducible highly detailed classifications are and emphasized that human hair varies widely across and within populations.

So if half your head seems to belong in one box and the other half keeps wandering into the box next door, I would not spend too much time forcing a verdict.

Your styling routine does not need your entire scalp to agree on a number.

It needs you to notice what the different sections do.

A curl chart can describe your hair. It does not get to overrule what is visibly growing from your head.

 

Your natural pattern and your visible pattern are not always identical

There is another reason two areas can look dramatically different on wash day: the shape coming from the follicle is only the beginning of the finished hairstyle.

Water temporarily changes the interactions within the keratin fibre. Preliminary 2025 research from the University of Cape Town specifically investigated weak hydrogen bonds involved in temporary shape changes in curly human hair.

That is part of why wetting, stretching, brushing and drying can temporarily make curls present differently without changing the follicle that produced them.

Styling technique matters too. One section may be brushed under tension while another is scrunched. Longer pieces may hang differently from shorter layers. A crown repeatedly smoothed against the scalp will not dry in the same position as curls underneath that were allowed to spring upward.

Then there is shrinkage. A tighter curl can lose considerably more apparent length as it dries than a looser neighbouring fibre, making differences that seemed small when wet suddenly look much larger.

This is why I would judge your mixed pattern after several normal wash days, not from one particularly enthusiastic brush-styling experiment.

 

Some sections may also have a completely different damage history

Now we get to the part where a pattern difference can be acquired rather than entirely natural.

Maybe you always straighten the front pieces.

Maybe highlights are concentrated around your face.

Maybe the crown gets more direct sun, brushing and diffuser heat than the protected layer underneath.

Chemical and physical treatments can alter the hair fibre. Studies of bleaching have documented changes in cuticle structure, protein loss, roughness and mechanical properties, while research has even demonstrated that alkaline peroxide treatment can alter fibre curvature in some hair.

That means a section looking looser than the rest does not automatically prove that its follicles naturally produce a looser curl.

Look at the newest few inches near the scalp.

If your roots form a curl and the same strand becomes progressively straighter, rougher or less springy through an older processed section, the history of that fibre deserves attention.

If the strand emerges from the scalp with the same looser shape it keeps all the way down, that is much more suggestive of natural pattern variation.

 

You are allowed to style different sections differently

This is where accepting mixed patterns becomes extremely practical.

If the loose section at your crown loses definition first, give it a little more hold or style it in smaller sections.

If your nape forms tight curls with almost no encouragement, perhaps it does not need the elaborate brush-styling routine you use around your face.

If one area is more weathered, concentrate additional conditioner there. If another becomes heavy easily, use less cream on that section.

The routine can vary across the same head.

That does not mean buying three completely separate product collections. Often it is as simple as changing the amount, technique or placement of the same products.

You might brush the looser crown sections for more consistent clumping but simply rake and scrunch the tighter underneath layer. You might use an extra touch of gel on curls that drop quickly while leaving tighter sections alone. You might finger-coil three stubborn pieces around the front rather than finger-coiling your entire head because three curls refused to cooperate.

Once you stop trying to make every fibre behave identically, styling can become considerably less exhausting.

 

And your pattern can look different as your hair changes

Even the curls produced by one person are not frozen in time.

A haircut changes length and removes older, weathered fibre. Growing out chemical processing reveals more of the natural shape coming from the follicle. Humidity and water temporarily influence hair mechanics and shape. Repeated bleaching or high heat can change the older fibre independently of the newer growth above it.

So you may genuinely look at your hair five years from now and describe it differently.

What deserves more attention is a sudden unexplained change accompanied by something else: significant breakage, a widening part, patchy loss, scalp inflammation or a marked reduction in density. Those are hair or scalp changes rather than simply an interesting mix of curl patterns, and a dermatologist can help determine what is happening.

Otherwise, there is no requirement that every section graduate into matching spirals.

Three curl patterns can live together beautifully.

So can two.

So can five.

The number is not particularly important.

Your hair is a collection of individual fibres, not a single curl enlarged thousands of times. Once you see it that way, the mixed pattern starts looking a lot less mysterious.

 

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Disclaimer: This article provides general hair-care information and is not a substitute for advice from a dermatologist or other qualified healthcare professional. Persistent breakage, scalp changes or sudden hair loss should be evaluated by a healthcare professional.