Development of sexuality is an integral part of the development and maturation of children. It includes a range of sensory, emotional, and consequent sexual activities that may occur before or during early puberty, but before full sexual maturity is established. The development of child sexuality and the perception of child sexuality by adults is influenced by social and cultural aspects. The concept of child sexuality also played an important role in psychoanalysis. Sexual development Before puberty The National Child Traumatic Stress Network issued a report in 2009 on child sexual development in the United States. The report asserted that children have a natural curiosity about their own bodies and the bodies of others that ought to be addressed in an age-appropriate manner. According to the report: Children less than four years old will normally touch their own private parts, look at the private parts of others, and remove their clothes wanting to be nude; Between ages four and six, children will be more actively curious. They will attempt to see others dressing or undressing, or will perhaps "play doctor"; and Between ages six and twelve, children will expand their curiosity to images of undressed people available in the media. They will develop a need for privacy regarding their own bodies and begin to be sexually attracted to peers. The report recommended that parents learn what is normal in regard to nudity and sexuality at each stage of a child's development and refrain from overreacting to their children's nudity-related behaviors unless there are signs of a problem (e.g. anxiety, aggression, or sexual interactions between children not of the same age or stage of development). Children can discover the pleasure of genital stimulation naturally at an early age. Boys often lie on their stomachs and girls may sit and rock. Manual stimulation occurs about the time of adolescence and mutual masturbation or other sexual experimentation between adolescents of similar ages may also occur, though cultural or religious coercion may inhibit or occult such activity if there is negative peer pressure or if authority figures are likely to disapprove. From the ages of three to seven, the following behaviors are normal among children: Children are curious about where babies come from. Children may explore other children's and adults' bodies out of curiosity. By age four, children may show significant attachment to the opposite-sex parent. Children begin to have a sense of learned modesty