Black hair has a flattened elliptical cross-sectional shape. This cross-sectional asymmetry accounts for the irregular kinky appearance of Black hair. Hispanic hair has a cross-sectional shape somewhere between a circle and a flattened ellipse giving it a wavy appearance. Other factors affecting the shape of hair are the chemical bonds that form within hair proteins. Curl is a factor of disulfide bonds within the keratin molecules.
Water is absorbed very rapidly causing the hair shaft to swell.
The mositure content, elasticity and tensile strength is lower in Black hair than in Caucasians. Reshaping or Styling Hair Hair can be reshaped by styling, such as by permanent-wave styling or straightening solutions. The perm or straightening solution breaks disulfide bonds that determine the amount of curl in the natural hair. The hair is mechanically reshaped into the desired configuration by using curlers, for example. Neutralizing solution neutralizes the styling chemicals that broke the disulfide bonds, so that the disulfide bonds can be reformed in the new configuration.