Voluntary sterilization is the most popular method of birth control in America. More than 1 million women and men choose to have the procedures every year. Sterilization is surgical birth control—it is intended to be permanent, and it is not easily reversed. Vasectomy is the surgical operation for men. It blocks the vas deferens. Tubal [...] medrx-one.com

Paraphilias That Rely on Consent Most paraphilias, like fetishism, are not dangerous and rely on the involvement of consenting partners. Here are some other common paraphilias that rely on consent: Pictophilia. Sexual arousal becomes dependent on viewing pornographic pictures, movies, or videos, with or without a partner. Transvestophilia. Sexual arousal becomes dependent on wearing clothing, [...]

Although the dependence of sexual behavior on gonadal hormones has been demonstrated in numerous experiments involving gonadectomy and hormonal replacement, there are very few research data available on the emergence of sexual behavior during spontaneous pubertal development. The most comprehensive studies on lower mammals have been reported by S?dersten and others who assessed sexual behavior [...]

Infants also can be divided into two categories based on the extent to which they seek close personal contacts—noncuddlers and cuddlers. Noncuddlers reach this developmental stage somewhat later than do cuddlers. Noncuddlers show displeasure at being restricted and contained from the early weeks, initially through restlessness. At nine or ten months, when they can crawl [...]

Rhesus monkeys, if pregnant with a daughter fetus and if injected with testosterone during a critical period, give birth to a baby with female internal reproductive organs (two ovaries, uterus, and fallopian tubes) and male external reproductive organs (a well-developed empty scrotum and a clitorine penis). These masculinized female (hermaphroditic) monkeys have been extensively studied [...]