This means that children and adults are exposed to media and advertising for several hours a day. Due to the fact that the brain does not fully develop until the age of 24; children and young adults are the urban class most vulnerable to the proliferation of media messages. Today, younger girls, between the ages of six and eight, are increasingly concerned about their physical appearance, because it is more emphasized and reinforced. The media shows children and young adults that their value lies in their youth, beauty and sexuality. When children watch TV they are constantly exposed to unattainable and unrealistic beauty standards, criteria that only a small percentage of women meet. Unrealistic media models send an implicit message that to be considered beautiful; you must be "unhealthy". Many children and young adults are also exposed to reality television. In reality television the media portrays that every woman is spiteful, bitchy, manipulative, vindictive and cannot be trusted, they are exposed to be judged and objectified by men (documentary). Researchers are unclear about how exposure to images in the media affects their physical appearance; although there are many different perspectives on how they might be affected. Some of these perspectives include social comparison,