Which factor is included among the four most important factors in a hair analysis besides texture, density, and porosity?

• A. Elasticity
• B. Shine
• C. Length
• D. Color

Answer: (A)

Elasticity is the ability of a hair strand to stretch under tension and then return to its original length, which reflects the strength of the hair’s cortex and the integrity of its keratin bonds. In a hair analysis, texture, density, and porosity tell you about surface feel, how many hairs are present, and how well the cuticle allows moisture to pass, but elasticity reveals how well the hair can withstand mechanical stress without breaking. Healthy hair with good elasticity stretches a bit and springs back; damaged hair becomes brittle, stretches less, and may snap under styling or brushing. That resilience is why elasticity is included as one of the four key factors. Shine, length, and color describe surface appearance, growth, or pigment and don’t directly indicate the hair’s mechanical resilience, so they aren’t among the main factors used in this analysis.