HAIR FACTS
soap |sōp|
a substance used with water for washing and cleaning, made of a compound of natural oils or fats with sodium hydroxide or another strong alkali, and typically having perfume and coloring added : a bar of soap.
a substance used with water for washing and cleaning, made of a compound of natural oils or fats with sodium hydroxide or another strong alkali, and typically having perfume and coloring added : a bar of soap.
NATURAL HAIR
All-natural
Some companies use "all-natural," "organic," "botanical," or "plant-derived" ingredients (such as plant extracts or oils), combining these additions with one or more typical surfactants.
Some companies use "all-natural," "organic," "botanical," or "plant-derived" ingredients (such as plant extracts or oils), combining these additions with one or more typical surfactants.
HAIR PIGMENTS
Human hair colorAll natural hair colors are the result of two types of hair pigment. Both of these pigments are types of melanin, produced inside the hair follicle and packed into granules found in the fibers. Eumelanin is the dominant pigment in dark-blond, brown, and black hair, while pheomelaninis dominant in red hair.[4] Blond hair is the result of having little pigmentation in the hair strand. Gray hair occurs when melanin decreases or disappears.
Human hair growthMain article: Human hair growthHair grows everywhere on the external body except for mucus membranes and glabrous skin, such as that found on the soles of the hands, feet, and lips.
Hair follows a specific growth cycle with three distinct and concurrent phases: anagen, catagen, and telogenphases. Each phase has specific characteristics that determine the length of the hair. All three phases occur simultaneously; one strand of hair may be in the anagen phase, while another is in the telogen phase.
The body has different types of hair, including vellus hairand androgenic hair, each with its own type of cellular construction. The different construction gives the hair unique characteristics, serving specific purposes, mainly warmth and protection.
FunctionMany mammals have fur and other hairs that serve different functions. Hair provides thermal regulation andcamouflage for many animals; for others it provides signals to other animals such as warnings, mating, or other communicative displays; and for some animals hair provides defensive functions and, rarely, even offensive protection. Hair also has a sensory function, extending the sense of touch beyond the surface of the skin. Guard hairs give warnings that may trigger a recoiling reaction.
Human hair growthMain article: Human hair growthHair grows everywhere on the external body except for mucus membranes and glabrous skin, such as that found on the soles of the hands, feet, and lips.
Hair follows a specific growth cycle with three distinct and concurrent phases: anagen, catagen, and telogenphases. Each phase has specific characteristics that determine the length of the hair. All three phases occur simultaneously; one strand of hair may be in the anagen phase, while another is in the telogen phase.
The body has different types of hair, including vellus hairand androgenic hair, each with its own type of cellular construction. The different construction gives the hair unique characteristics, serving specific purposes, mainly warmth and protection.
FunctionMany mammals have fur and other hairs that serve different functions. Hair provides thermal regulation andcamouflage for many animals; for others it provides signals to other animals such as warnings, mating, or other communicative displays; and for some animals hair provides defensive functions and, rarely, even offensive protection. Hair also has a sensory function, extending the sense of touch beyond the surface of the skin. Guard hairs give warnings that may trigger a recoiling reaction.
HAIR CONDITIONERS
A 19th-century advertisement for 9 haircare products from a company named Dupuy.conditioneris a hair careproduct thatalters thetexture and appearance of human hair.
History
For centuries, natural oils have been used to condition human hair. These natural products are still used today, including essential oils such as tea tree oil and carrier oilssuch as jojoba oil. A conditioner popular with men in the late Victorian era was Macassar oil, but this product was quite greasy and required pinning a small cloth, known as an antimacassar, to chairs and sofas to keep the upholstery from being damaged by the Macassar oil.
Modern hair conditioner was created at the turn of the 20th century when well-known perfumer Ed. Pinaudpresented a product he called brilliantine at the 1900Exposition Universelle in Paris. His product was intended to soften men's hair, including beards and mustaches. Since the invention of Pinaud's early products, modern science has advanced the hair conditioner industry to include those made with silicone, fatty alcohols, andquaternary ammonium compounds. These chemical products allow the benefits of hair conditioner without feeling greasy or heavy.
Hair conditioner is different from cream rinse (often spelled "creme rinse"). A cream rinse is simply a detangler and, as its name implies, has a thinner consistency than conditioner. Hair conditioner is a thicker substance which coats the cuticle of the hair itself
IngredientsThere are several types of hair conditioner ingredients, differing in composition and functionality:
Types
History
For centuries, natural oils have been used to condition human hair. These natural products are still used today, including essential oils such as tea tree oil and carrier oilssuch as jojoba oil. A conditioner popular with men in the late Victorian era was Macassar oil, but this product was quite greasy and required pinning a small cloth, known as an antimacassar, to chairs and sofas to keep the upholstery from being damaged by the Macassar oil.
Modern hair conditioner was created at the turn of the 20th century when well-known perfumer Ed. Pinaudpresented a product he called brilliantine at the 1900Exposition Universelle in Paris. His product was intended to soften men's hair, including beards and mustaches. Since the invention of Pinaud's early products, modern science has advanced the hair conditioner industry to include those made with silicone, fatty alcohols, andquaternary ammonium compounds. These chemical products allow the benefits of hair conditioner without feeling greasy or heavy.
Hair conditioner is different from cream rinse (often spelled "creme rinse"). A cream rinse is simply a detangler and, as its name implies, has a thinner consistency than conditioner. Hair conditioner is a thicker substance which coats the cuticle of the hair itself
IngredientsThere are several types of hair conditioner ingredients, differing in composition and functionality:
- Moisturizers, whose role is to hold moisture in the hair. Usually these contain high proportions ofhumectants.
- Reconstructors, usually containing hydrolyzed protein. Their role is supposedly to penetrate the hair and strengthen its structure through polymer crosslinking.
- Acidifiers, acidity regulators which maintain the conditioner's pH at about 3.5. In contact with acidicenvironment, the hair's somewhat scaly surface tightens up, as the hydrogen bonds between thekeratin molecules are strengthened.
- Detanglers, which modify the hair surface by pH as acidifiers, and/or by coating it with polymers, as glossers.
- Thermal protectors, usually heat-absorbing polymers, shielding the hair against excessive heat, caused by, e.g., blow-drying or curling irons or hot rollers.
- Glossers, light-reflecting chemicals which bind to the hair surface. Usually polymers, usually silicones, e.g., dimethicone or cyclomethicone.
- Oils (EFAs - essential fatty acids), which can help dry/porous hair become more soft and pliable. The scalp produces a natural oil called sebum. EFAs are the closest thing to natural sebum (sebum contains EFAs).
- Surfactants - Hair consists of approximately 97% of a protein called keratin. The surface of keratin contains negatively-charged amino acids. Hair conditioners therefore usually contain cationicsurfactants, which don't wash out completely, because their hydrophilic ends strongly bind to keratin. Thehydrophobic ends of the surfactant molecules then act as the new hair surface.
- Lubricants, such as fatty alcohols, panthenol,dimethicone, etc
- Sequestrants, for better function in hard water.
- Antistatic agents
- Preservatives
Types
- Pack conditioners, are heavy and thick, with a high content of surfactants able to bind to the hair structure and "glue" the hair surface scales together. These are usually applied to the hair for a longer time. The surfactants are based on long straight aliphatic chains similar to saturated fatty acids. Their molecules have a tendency to crystallize easily, giving the conditioner higher viscosity, and they tend to form thicker layers on the hair surface.
- Leave-in conditioners are thinner and have different surfactants which add only a little material to the hair. They are based on unsaturated chains, which are bent rather than straight. This shape makes them less prone to crystallizing, making a lighter, less viscous mixture and providing significantly thinner layer on the hair. The difference between leave-in and pack conditioners is similar to the difference between fats and oils.
- Ordinary conditioners, combining some aspects of both pack and leave-in ones.
- Hold conditioners, based on cationic polyelectrolytepolymers, holding the hair in a desired shape. These have both the function and the composition similar to diluted hair gels.
PROTECTING OUR HAIR
Protection
Human hair may not compete with the painful spines of the porcupine, but much of the hair on the human body is suited to protect it. This natural armor cannot directly protect humans from potential predators, but it does help to keep the sense organs, such as the eyes, working properly.
Touch senseMovements of hair shafts are detected by nerve receptors within the skin and by hair follicle receptors through displacement and vibration of hair shafts. Hairs can sense movements of air as well as touch by physical objects and are especially sensitive to the presence of insects. Some hairs, such as eyelashes, are especially sensitive to the presence of potentially harmful matter.[11][12][13]
Eyebrows and eyelashesEyelashes and eyebrows help to protect the eyes from dust, dirt, and sweatThe eyebrows are situated above theeyelids on theforehead. In many other mammals they contain much longer hairs that are upright, functioning as tactile sensors. While they have little significance to the survival of humans, they remain a part of the body's physiological makeup because of the role they play in protecting the eyes from dirt,sweat, and rain, as well as non-verbalcommunication.[14] People have developed other means, such as hats, umbrellas, and goggles to serve the purpose of eyebrows more effectively, but the presence of eyebrows may suggest that they were once important to earlier species' survival.[14]
The eyelash grows at the edges of the eyelid and protects the eye from dirt entering the eye. Camels have particularly long and thick eyelashes. The eyelash is to humans, camels, horses, ostriches etc., what whiskers are to cats; they are used to sense when dirt, dust, or any other potentially harmful object is too close to the eye.[15]The eye reflexively closes as a result of this sensation.
Human hair may not compete with the painful spines of the porcupine, but much of the hair on the human body is suited to protect it. This natural armor cannot directly protect humans from potential predators, but it does help to keep the sense organs, such as the eyes, working properly.
Touch senseMovements of hair shafts are detected by nerve receptors within the skin and by hair follicle receptors through displacement and vibration of hair shafts. Hairs can sense movements of air as well as touch by physical objects and are especially sensitive to the presence of insects. Some hairs, such as eyelashes, are especially sensitive to the presence of potentially harmful matter.[11][12][13]
Eyebrows and eyelashesEyelashes and eyebrows help to protect the eyes from dust, dirt, and sweatThe eyebrows are situated above theeyelids on theforehead. In many other mammals they contain much longer hairs that are upright, functioning as tactile sensors. While they have little significance to the survival of humans, they remain a part of the body's physiological makeup because of the role they play in protecting the eyes from dirt,sweat, and rain, as well as non-verbalcommunication.[14] People have developed other means, such as hats, umbrellas, and goggles to serve the purpose of eyebrows more effectively, but the presence of eyebrows may suggest that they were once important to earlier species' survival.[14]
The eyelash grows at the edges of the eyelid and protects the eye from dirt entering the eye. Camels have particularly long and thick eyelashes. The eyelash is to humans, camels, horses, ostriches etc., what whiskers are to cats; they are used to sense when dirt, dust, or any other potentially harmful object is too close to the eye.[15]The eye reflexively closes as a result of this sensation.
THE VARIOUS HAIR TEXTURES
Curly hair
Jablonski agrees that it was evolutionarily advantageous for pre-humans to retain the hair on their heads in order to protect the scalp as they walked upright in the intense African (equatorial) UV light. While some might argue that, by this logic, humans should also express hairy shoulders given that these body parts would putatively be exposed to similar conditions, the protection of the head, the seat of the brain that enabled humanity to become one of the most successful species on the planet (and which also is very vulnerable at birth), was arguably a more urgent issue (axillary hair in the underarms and groin were also retained as signs of sexual maturity). During the gradual process by which Homo erectus made a transition from furry to naked skin, their hair texture putatively changed gradually from straight[citation needed](the condition of most mammals, including humanity's closest cousins—chimpanzees), to Afro-like or 'kinky' (i.e. tightly coiled). In this sense, during the period in which humans were gradually losing their straight body hair and thereby exposing initially the pale skin underneath their fur to the sun, straight hair would have been an adaptive liability. Hence, tightly coiled or 'kinky' Afro-hair may have evolved to prevent the entry of UV light into the body during the transition toward dark, UV-protected skin.
Alternatively, some intuit that tightly coiled hair that grows into a typical Afro-like formation would have greatly reduced the ability of the head and brain to cool. They reason that although hair density in African peoples is much less than their European counterparts, in the intense sun the effective 'woolly hat' produced would have been a disadvantage. However, anthropologists such as Nina Jablonski make the opposite argument with regards to this hair texture. Specifically, Jablonski's assertions [28] suggest that the adjective "woolly" in reference to Afro-hair is a misnomer to the extent that it connotes the high heat insulation derivable from the true wool of sheep. Instead, the relatively sparse density of Afro-hair, combined with its springy coils actually results in an airy, almost sponge-like effect. This, in turn, Jablonski argues,[28] more likely facilitates an increase in the circulation of cool air onto the scalp. Further, Afro-hair does not respond so easily to moisture and sweat as straight hair. Thus it does not stick to the neck and scalp when wet. Rather, unless totally drenched, it tends to retain its basic springy puffiness. In this sense, the trait may enhance comfort levels in intense equatorial climates compared to straight hair (which, on the other hand, tends to naturally fall over the ears and neck to a degree that provides slightly enhanced comfort levels in cold climates relative to tightly coiled hair).
Further, some interpret the ideas of Charles Darwin as suggesting that some traits, such as hair texture, were so arbitrary to human survival that the role natural selection played was trivial. They argue that Darwin's explanation which was that sexual selection may be responsible for such traits.[31] However, the concept of "triviality" is a human value judgment, and hair texturestill may have played a role. In fact, while the sexual selection hypothesis cannot be ruled out, the asymmetrical distribution of this trait vouches for environmental influence. Specifically, if hair texture were simply the result of adaptively arbitrary human aesthetic preferences, one would expect that the global distribution of the various hair textures would be fairly random.Instead, the distribution of Afro-hair is strongly skewed toward the equator. Further, it is notable that the most pervasive expression of this hair texture can be found in sub-Saharan Africa; a region of the world that abundant genetic and paleo-anthropological evidence suggests, was the relatively recent (~200,000 year old) point of origin for modern humanity. In fact, although genetic findings (Tishkoff, 2009) suggest that sub-Saharan Africans are the most genetically diverse continental group on Earth, Afro-textured hair (along with a small cluster of other physical features) approaches ubiquity is this region.[citation needed] This points to a strong, long-term selective pressure that, in stark contrast to most other regions of the genomes of sub-Saharan groups, left little room for genetic variation at the determining loci. Such a pattern is, again, not indicative of human sexual aesthetics.
Straight hairAccording to the recent single origin hypothesis, anatomically modern humans arose in East Africa approximately 200,000 years ago (Tishkoff, 1996). Then, ~150,000 years later, modern humans began to expand their range to regions outside of (and within) this continent (Tishkoff, 1996). The skin of those in the group that left the African continent had developed the ability to manufacture vitamin D (which was essential for bone development) upon exposure to UV light.[28] However, the UV light of northern regions was too weak to penetrate the highly pigmented skin of the initial migrants in order to provide enough vitamin D for healthy bone development.[28] Malformed bones in the pelvic area were especially deadly for women because they interfered with the successful delivery of babies; leading to the death of both the mother and the infant during labor. Hence, those with lighter skin survived and had children at higher rates because their skin allowed more UV light for the production of vitamin D.[28]
Man with straight hairIn this sense, the evidence with regard to the evolution of straight hair texture seems to support Jablonski's suggestions [28]that the need for vitamin D triggered the transition back from dark to light skin. Specifically, the distribution of this trait suggests that this need may have grown so intense at certain points that Northerners with mutations for straighter hair survived and had children at higher rates. This argument is made based on the principle that straight fibers better facilitate the passage of UV light into the body relative to curly hair. It is substantiated by Iyengar's (1998) findings that UV light can pass through straight human hair roots in a manner similar to the way that light passes through fiber optic tubes (Iyengar, 1998).
Nonetheless, some argue against this stance because straighter hair ends tend to point downward while fiber optics requires that light be transmitted at a high angle to the normal of the inner reflective surface. In light of this, they suggest that only light reflected from the ground could successfully enter the hair follicle and be transmitted down the shaft. Even this process, they argue, is hindered by the curvature at the base of the hair. Therefore, coupled with the amount of skin covered by long head hair, these factors seem to militate against the adaptive usefulness of straight hair at northern latitudes. They further argue that UV light also is poorly reflected from soil and dull surfaces. These ideas can be countered by the fact that during the winter, the time of year in which UV light is most scarce at northern latitudes, the ground is often covered with white snow. Given that white is the most effective color in terms of facilitating the reflection of ground light, the hypothesis that straight hair could have been adaptively favorable, cannot be fully discounted in this regard. In addition, as mentioned in the previous section, straight hair also may have contributed to enhanced comfort levels in the north. This is evident in the extent to which, relative to curly hair, it tends to provide a layer of protection for ears and necks against the cold.
The latter hypothesis seems the more plausible evolution determinant as the surface area of the head is minute compared to the remainder of the body, thus the energy required in producing long hair for the express purpose of "optical" amplification of UV light reflected from the snow seems counterproductive. Scientists point to the fact that straight hair found in many ethnic groups is denser as well and has a greater ability to "show" as it does not coil, hence providing more warmth as the likely deterministic factor for the evolution of straight long hair. Some scientists argue that since the head and appendages are the greatest areas for heat loss from the body, the ability to grow long hair on the crown of the head as well as the face provides a distinct advantage in a cold climate. Since the main sensory organs are anatomically located on the head, long hair provides the necessary warmth and protection in a cold climate that allows the use of these organs by exposing them to the elements to "sense", in for example a hunt, yet still providing necessary warmth and protection to sustain prolonged exposure. It may be argued, therefore, that the ability to grow long, straight, densely packed hair provides a distinct evolutionary advantage in cold climate; however, it would be a distinct disadvantage in a hot climate, when compared to loosely packed, spongy, closely cropped hair.
Jablonski agrees that it was evolutionarily advantageous for pre-humans to retain the hair on their heads in order to protect the scalp as they walked upright in the intense African (equatorial) UV light. While some might argue that, by this logic, humans should also express hairy shoulders given that these body parts would putatively be exposed to similar conditions, the protection of the head, the seat of the brain that enabled humanity to become one of the most successful species on the planet (and which also is very vulnerable at birth), was arguably a more urgent issue (axillary hair in the underarms and groin were also retained as signs of sexual maturity). During the gradual process by which Homo erectus made a transition from furry to naked skin, their hair texture putatively changed gradually from straight[citation needed](the condition of most mammals, including humanity's closest cousins—chimpanzees), to Afro-like or 'kinky' (i.e. tightly coiled). In this sense, during the period in which humans were gradually losing their straight body hair and thereby exposing initially the pale skin underneath their fur to the sun, straight hair would have been an adaptive liability. Hence, tightly coiled or 'kinky' Afro-hair may have evolved to prevent the entry of UV light into the body during the transition toward dark, UV-protected skin.
Alternatively, some intuit that tightly coiled hair that grows into a typical Afro-like formation would have greatly reduced the ability of the head and brain to cool. They reason that although hair density in African peoples is much less than their European counterparts, in the intense sun the effective 'woolly hat' produced would have been a disadvantage. However, anthropologists such as Nina Jablonski make the opposite argument with regards to this hair texture. Specifically, Jablonski's assertions [28] suggest that the adjective "woolly" in reference to Afro-hair is a misnomer to the extent that it connotes the high heat insulation derivable from the true wool of sheep. Instead, the relatively sparse density of Afro-hair, combined with its springy coils actually results in an airy, almost sponge-like effect. This, in turn, Jablonski argues,[28] more likely facilitates an increase in the circulation of cool air onto the scalp. Further, Afro-hair does not respond so easily to moisture and sweat as straight hair. Thus it does not stick to the neck and scalp when wet. Rather, unless totally drenched, it tends to retain its basic springy puffiness. In this sense, the trait may enhance comfort levels in intense equatorial climates compared to straight hair (which, on the other hand, tends to naturally fall over the ears and neck to a degree that provides slightly enhanced comfort levels in cold climates relative to tightly coiled hair).
Further, some interpret the ideas of Charles Darwin as suggesting that some traits, such as hair texture, were so arbitrary to human survival that the role natural selection played was trivial. They argue that Darwin's explanation which was that sexual selection may be responsible for such traits.[31] However, the concept of "triviality" is a human value judgment, and hair texturestill may have played a role. In fact, while the sexual selection hypothesis cannot be ruled out, the asymmetrical distribution of this trait vouches for environmental influence. Specifically, if hair texture were simply the result of adaptively arbitrary human aesthetic preferences, one would expect that the global distribution of the various hair textures would be fairly random.Instead, the distribution of Afro-hair is strongly skewed toward the equator. Further, it is notable that the most pervasive expression of this hair texture can be found in sub-Saharan Africa; a region of the world that abundant genetic and paleo-anthropological evidence suggests, was the relatively recent (~200,000 year old) point of origin for modern humanity. In fact, although genetic findings (Tishkoff, 2009) suggest that sub-Saharan Africans are the most genetically diverse continental group on Earth, Afro-textured hair (along with a small cluster of other physical features) approaches ubiquity is this region.[citation needed] This points to a strong, long-term selective pressure that, in stark contrast to most other regions of the genomes of sub-Saharan groups, left little room for genetic variation at the determining loci. Such a pattern is, again, not indicative of human sexual aesthetics.
Straight hairAccording to the recent single origin hypothesis, anatomically modern humans arose in East Africa approximately 200,000 years ago (Tishkoff, 1996). Then, ~150,000 years later, modern humans began to expand their range to regions outside of (and within) this continent (Tishkoff, 1996). The skin of those in the group that left the African continent had developed the ability to manufacture vitamin D (which was essential for bone development) upon exposure to UV light.[28] However, the UV light of northern regions was too weak to penetrate the highly pigmented skin of the initial migrants in order to provide enough vitamin D for healthy bone development.[28] Malformed bones in the pelvic area were especially deadly for women because they interfered with the successful delivery of babies; leading to the death of both the mother and the infant during labor. Hence, those with lighter skin survived and had children at higher rates because their skin allowed more UV light for the production of vitamin D.[28]
Man with straight hairIn this sense, the evidence with regard to the evolution of straight hair texture seems to support Jablonski's suggestions [28]that the need for vitamin D triggered the transition back from dark to light skin. Specifically, the distribution of this trait suggests that this need may have grown so intense at certain points that Northerners with mutations for straighter hair survived and had children at higher rates. This argument is made based on the principle that straight fibers better facilitate the passage of UV light into the body relative to curly hair. It is substantiated by Iyengar's (1998) findings that UV light can pass through straight human hair roots in a manner similar to the way that light passes through fiber optic tubes (Iyengar, 1998).
Nonetheless, some argue against this stance because straighter hair ends tend to point downward while fiber optics requires that light be transmitted at a high angle to the normal of the inner reflective surface. In light of this, they suggest that only light reflected from the ground could successfully enter the hair follicle and be transmitted down the shaft. Even this process, they argue, is hindered by the curvature at the base of the hair. Therefore, coupled with the amount of skin covered by long head hair, these factors seem to militate against the adaptive usefulness of straight hair at northern latitudes. They further argue that UV light also is poorly reflected from soil and dull surfaces. These ideas can be countered by the fact that during the winter, the time of year in which UV light is most scarce at northern latitudes, the ground is often covered with white snow. Given that white is the most effective color in terms of facilitating the reflection of ground light, the hypothesis that straight hair could have been adaptively favorable, cannot be fully discounted in this regard. In addition, as mentioned in the previous section, straight hair also may have contributed to enhanced comfort levels in the north. This is evident in the extent to which, relative to curly hair, it tends to provide a layer of protection for ears and necks against the cold.
The latter hypothesis seems the more plausible evolution determinant as the surface area of the head is minute compared to the remainder of the body, thus the energy required in producing long hair for the express purpose of "optical" amplification of UV light reflected from the snow seems counterproductive. Scientists point to the fact that straight hair found in many ethnic groups is denser as well and has a greater ability to "show" as it does not coil, hence providing more warmth as the likely deterministic factor for the evolution of straight long hair. Some scientists argue that since the head and appendages are the greatest areas for heat loss from the body, the ability to grow long hair on the crown of the head as well as the face provides a distinct advantage in a cold climate. Since the main sensory organs are anatomically located on the head, long hair provides the necessary warmth and protection in a cold climate that allows the use of these organs by exposing them to the elements to "sense", in for example a hunt, yet still providing necessary warmth and protection to sustain prolonged exposure. It may be argued, therefore, that the ability to grow long, straight, densely packed hair provides a distinct evolutionary advantage in cold climate; however, it would be a distinct disadvantage in a hot climate, when compared to loosely packed, spongy, closely cropped hair.
CUTTING AND TRIMMING HAIR
Cutting and trimmingBecause the hair on the head is normally longer than other types of body hair, it is cut with scissors or clippers. People with longer hair will most often use scissors to cut their hair, whereas shorter hair is maintained using a trimmer. Depending on the desired length and overall health of the hair, periods without cutting or trimming the hair can vary.
Many people will confuse what a haircut is versus what a trim is. A haircut is usually performed in order to change one's hairstyle, while a trim helps to keep away split endsand keep the hair well-groomed. Cutting hair tends to take off more hair than trimming hair does. When hair is trimmed, only the first few centimeters need to be removed, whereas haircuts can sometimes result in the loss of many inches of hair.
Many people will confuse what a haircut is versus what a trim is. A haircut is usually performed in order to change one's hairstyle, while a trim helps to keep away split endsand keep the hair well-groomed. Cutting hair tends to take off more hair than trimming hair does. When hair is trimmed, only the first few centimeters need to be removed, whereas haircuts can sometimes result in the loss of many inches of hair.
THE ROLE HAIR PLAYS SOCIALLY
Social roleSee also: HairstylePortrait of a Woman, Alessandro Allori (1535 – 1607; Uffizi Gallery): a plucked hairline gives a fashionably "noble brow"Hair has great social significance for human beings. It can grow on most external areas of thehuman body, except on the palms of the handsand the soles of the feet (among other areas). Hair is most noticeable on most people in a small number of areas, which are also the ones that are most commonly trimmed, plucked, or shaved. These include the face, ears, head, eyebrows, legs, and armpits, as well as the pubic region. The highly visible differences between male and female body and facial hair are a notable secondary sex characteristic.
Indication of statusHealthy hair indicates health and youth (important inevolutionary biology). Hair colour and texture can be a sign of ethnic ancestry. Facial hair is a sign of puberty in men. White hair is a sign of age or genetics, which may be concealed with hair dye. Male pattern baldness is a sign of age, which may be concealed with a toupee, hats, or religious and cultural adornments. Although drugs and medical procedures exist for the treatment of baldness, many balding men simply shave their heads.Hair whorls have been discovered to be associated withbrain development.
Hairstyle may be an indicator of group membership. During the English Civil War, the followers of Oliver Cromwell decided to crop their hair close to their head, as an act of defiance to the curls and ringlets of the king's men.[35] This led to the Parliamentary faction being nicknamed Roundheads. Having bobbed hair was popular among the flappers in the 1920s as a sign of rebellion against traditional roles for women. Female art students known as the "cropheads" also adopted the style, notably at the Slade School in London, England. Regional variations in hirsutism cause practices regarding hair on the arms and legs to differ. Some religious groups may follow certain rules regarding hair as part of religious observance. The rules often differ for men and women.
Many subcultures have hairstyles which may indicate an unofficial membership. Many hippies, metalheads, and Indian sadhus have long hair. Many punks wear a hairstyle known as a Mohawk or other spiked and dyed hairstyles; skinheads have short-cropped or completely shaved heads. Mullet hairstyles stereotypically have been associated with rednecks.[citation needed]
Heads were shaved in concentration camps, and head-shaving has been used as punishment, especially for women with long hair. The shaven head is common inmilitary haircuts, while Western monks are known for thetonsure. By contrast, among some Indian holy men, the hair is worn extremely long.[citation needed]
The ethnically Manchu Qing Dynasty, beginning in the late seventeenth century China, ordered all Chinese citizens to adopt Manchurian hairstyles by shaving the front of their head and adopting a queue.[citation needed]
Regular hairdressing in some cultures is considered a sign of wealth or status. The dreadlocks of the Rastafari movement were despised early in the movement's history. In some cultures, having one's hair cut can symbolize a liberation from one's past, usually after a trying time in one's life. Cutting the hair also may be a sign of mourning.
Tightly coiled hair in its natural state may be worn in anAfro. This hairstyle was once worn among African Americans as a symbol of racial pride. Given that the coiled texture is the natural state of some African Americans' hair, or perceived as being more "African", this simple style is now often seen as a sign of self-acceptance and an affirmation that the beauty norms of dominant (northern/European) culture are not absolute. It is important to note that African Americans as a whole have a variety of hair textures, as they are not an ethnically homogeneous mixture, but an Ad-Hoc of many ethnicities, one component being African. It is also to note that "Afro Hair" is not universal in Africa as well, although is common among many "West African" ethnicities.[citation needed]
The film Easy Rider (1969) includes the assumption that the two main characters could have their long hairs forcibly shaved with a rusty razor when jailed, symbolizing the intolerance of some conservative groups toward members of the counterculture.
At the conclusion of the Oz obscenity trials in the UK, the defendants had their heads shaved by the police, causing public outcry. During the appeal trial, they appeared in the dock wearing wigs.[citation needed]
Religious practicesWomen's hair may be hidden using headscarves, a common part of the hijab in Islam and a symbol of modesty required for certain religious rituals in Orthodox Christianity. Orthodox Judaism endorses the use ofscarves and other head coverings for women for modestyreasons as in Islam. Sikhs generally keep their hair uncut and men keep it tied in a bun on the head, which is then covered appropriately using a turban.
Indication of statusHealthy hair indicates health and youth (important inevolutionary biology). Hair colour and texture can be a sign of ethnic ancestry. Facial hair is a sign of puberty in men. White hair is a sign of age or genetics, which may be concealed with hair dye. Male pattern baldness is a sign of age, which may be concealed with a toupee, hats, or religious and cultural adornments. Although drugs and medical procedures exist for the treatment of baldness, many balding men simply shave their heads.Hair whorls have been discovered to be associated withbrain development.
Hairstyle may be an indicator of group membership. During the English Civil War, the followers of Oliver Cromwell decided to crop their hair close to their head, as an act of defiance to the curls and ringlets of the king's men.[35] This led to the Parliamentary faction being nicknamed Roundheads. Having bobbed hair was popular among the flappers in the 1920s as a sign of rebellion against traditional roles for women. Female art students known as the "cropheads" also adopted the style, notably at the Slade School in London, England. Regional variations in hirsutism cause practices regarding hair on the arms and legs to differ. Some religious groups may follow certain rules regarding hair as part of religious observance. The rules often differ for men and women.
Many subcultures have hairstyles which may indicate an unofficial membership. Many hippies, metalheads, and Indian sadhus have long hair. Many punks wear a hairstyle known as a Mohawk or other spiked and dyed hairstyles; skinheads have short-cropped or completely shaved heads. Mullet hairstyles stereotypically have been associated with rednecks.[citation needed]
Heads were shaved in concentration camps, and head-shaving has been used as punishment, especially for women with long hair. The shaven head is common inmilitary haircuts, while Western monks are known for thetonsure. By contrast, among some Indian holy men, the hair is worn extremely long.[citation needed]
The ethnically Manchu Qing Dynasty, beginning in the late seventeenth century China, ordered all Chinese citizens to adopt Manchurian hairstyles by shaving the front of their head and adopting a queue.[citation needed]
Regular hairdressing in some cultures is considered a sign of wealth or status. The dreadlocks of the Rastafari movement were despised early in the movement's history. In some cultures, having one's hair cut can symbolize a liberation from one's past, usually after a trying time in one's life. Cutting the hair also may be a sign of mourning.
Tightly coiled hair in its natural state may be worn in anAfro. This hairstyle was once worn among African Americans as a symbol of racial pride. Given that the coiled texture is the natural state of some African Americans' hair, or perceived as being more "African", this simple style is now often seen as a sign of self-acceptance and an affirmation that the beauty norms of dominant (northern/European) culture are not absolute. It is important to note that African Americans as a whole have a variety of hair textures, as they are not an ethnically homogeneous mixture, but an Ad-Hoc of many ethnicities, one component being African. It is also to note that "Afro Hair" is not universal in Africa as well, although is common among many "West African" ethnicities.[citation needed]
The film Easy Rider (1969) includes the assumption that the two main characters could have their long hairs forcibly shaved with a rusty razor when jailed, symbolizing the intolerance of some conservative groups toward members of the counterculture.
At the conclusion of the Oz obscenity trials in the UK, the defendants had their heads shaved by the police, causing public outcry. During the appeal trial, they appeared in the dock wearing wigs.[citation needed]
Religious practicesWomen's hair may be hidden using headscarves, a common part of the hijab in Islam and a symbol of modesty required for certain religious rituals in Orthodox Christianity. Orthodox Judaism endorses the use ofscarves and other head coverings for women for modestyreasons as in Islam. Sikhs generally keep their hair uncut and men keep it tied in a bun on the head, which is then covered appropriately using a turban.