stated, "The idea that early sexual activity and pregnancy is linked to low self-esteem became fashionable in the latter half of the 20th century, particularly in the US," adding that, "Yet, in a systematic review of the relationship between self-esteem and teenagers' sexual behaviours, attitudes and intentions (which analyzed findings from 38 publications) 62% of behavioral findings and 72% of the attitudinal findings exhibited no statistically significant associations (Goodson et al, 2006)." Studies that do find a link suggest that non-virgin boys have higher self-esteem than virgin boys and that girls who have low self-esteem and poor self-image are more prone to risk-taking behaviors, such as unprotected sex and multiple sexual partners. Psychiatrist Lynn Ponton wrote, "All adolescents have sex lives, whether they are sexually active with others, with themselves, or seemingly not at all", and that viewing adolescent sexuality as a potentially positive experience, rather than as something inherently dangerous, may help young people develop healthier patterns and make more positive choices regarding sexual activity. Researchers state that long-term romantic relationships allow adolescents to gain the skills necessary for high-quality relationships later in life. Overall, positive romantic relationships among adolescents can result in long-term benefits. High-quality romantic relationships are associated with higher commitment in early adulthood, and are positively associated with social competence. Ethical, religious, and legal views General While sexual intercourse, as coitus, is the natural mode of reproduction for the human species, humans have intricate moral and ethical guidelines which regulate the practice of sexual intercourse and vary according to religious and governmental laws. Some governments and religions also have strict designations of what they consider appropriate and inappropriate sexual behavior, which include restrictions on the types of sex acts which are permissible. A historically prohibited or regulated sex act is anal sex. Sexual offenses Sexual intercourse with a person against their will, or without their consent, is rape, but may also be called sexual assault; it is considered a serious crime in most countries. More than 90% of rape victims are female, 99% of rapists male, and only about 5% of rapists are strangers to the victims. Most countries have age of consent laws which set the minimum legal age with whom an older person may engage in sexual intercourse, usually set at 16 to 18, but ranges from 12 to 20, years of age. In some societies, an age of consent is set by non-statutory