Some cultural critics have postulated that over recent decades children have evidenced a level of sexual knowledge or sexual behavior inappropriate for their age group. The causes of this premature sexualization that have been cited include portrayals in the media of sex and related issues, especially in media aimed at children; the marketing of products with sexual connotations to children, including clothing; the lack of parental oversight and discipline; access to adult culture via the internet; and the lack of comprehensive school sex education programs. For girls and young women in particular, studies have found that sexualization has a negative impact on their “self-image and healthy development”. Research has linked sexualization with three of the most common mental health problems diagnosed in girls and women: eating disorders, low self-esteem, and depression or depressed mood.