Types and Characteristics of Hair Across the Globe: Results of a Multinational Study on 19,461 Individuals.

Introduction: Hair plays a critical role in enhancing physical appearance, self-esteem, and identity. However, the impact of hair characteristics on daily life has received limited attention. This study aimed to assess the types and characteristics of hair, their variations according to age, gender, ethnicity, and country, and their effects on individuals' daily lives. Methods: A study was conducted between February 2022 and June 2023 across nine countries: USA, France, Brazil, India, China, Mexico, Japan, South Africa, and Indonesia. A total of 19,461 participants aged 18 and older were selected using stratified, proportional sampling. Participants completed a structured digital questionnaire evaluating hair thickness, type, damage, and curl degree, alongside questions on stress, sleep, and well-being. Data were analyzed using descriptive statistics and statistical tests ( Results: Thin hair was reported by 23.7% of males and 29.2% of females. Dry hair was more common in females (38.9%) than males (32.1%). Damaged hair was reported by 47% of females and 30% of males. Ethnic differences showed that thick hair was most common in African (40.7%) and least in Asian (26.3%) populations. The impact of hair type on daily life varied significantly across countries. Individuals with damaged or dry hair experienced higher stress, lack of sleep, and poor well-being, especially in Japan, India, and France. Hair type (straight, wavy, curly, kinky) also affected personal and professional stress levels differently in each country. Conclusion: Our research shows that hair characteristics significantly influence daily life, self-image, and well-being, with notable variations by gender, ethnicity, and country. These findings highlight the need for interventions to address the psychological and social impacts of hair issues, contributing to better healthcare, body image, and product development.