The onset of adolescence--the period of transition between childhood and adulthood--is usually accompanied by dramatic and often difficult changes in the life of a young person. Biological, cognitive, social, and environmental factors all contribute to influence an adolescent's personal development and self-esteem. Studies have shown that adolescent girls tend to have lower self-esteem and more negative assessments of their physical characteristics and intellectual abilities than boys have. These findings may explain why the incidence of suicide attempts, depression, and eating disorders is substantially higher in girls. Future research on methods for promoting self-esteem may help reduce the negative feelings of adolescent girls, as well as the problems that stem from them.