Sexual reproduction even in plants (pollination) involves pollen being transferred (by wind or bees, for example) from the male reproductive part (the anther, part of the stamen) to the female reproductive part (the stigma, the tip of the pistil) of the plant. The male part is active and the female part is static. This is how sexual reproduction is defined throughout Nature.
In humans (and other mammals) the male is attracted to a female and is the initiator and the proactive driver of the mating act, by which a sperm cell (ejaculated from the penis) joins with an egg cell produced each month by the woman’s body. The problem comes when we assume that an act of impregnation causes female orgasm. Male arousal is vital to reproduction because a man needs an erection to ejaculate into a vagina. Female responsiveness has no role in reproduction and nothing to do with intercourse.
The role of intercourse is well understood and the temptation is to believe that the mating act not only impregnates women but also provides them with an orgasm. In fact, the opposite is true. Intercourse is a risk-free activity for men but, for women, intercourse can cause pregnancy. Men think nothing of this risk because they are not the ones left holding the baby. This penalty means women instinctively avoid intercourse. Only masturbation alone allows a woman to enjoy risk-free sexual pleasure in the way that a man enjoys intercourse. We can say that women are sexually passive with a lover. But it is equally true to say that, due to her lack of arousal, a woman has a conscious choice over the man she allows to impregnate her.
Girls learn that men seek sexual contact (indeed all forms of physical intimacy). Women do not talk of their own desire to explore a man’s body or need for penetration. They rarely refer explicitly to male sexual anatomy. They do not talk of sexual pleasure. They talk of their hopes for a considerate and charming lover who is respectful and caring. Women are concerned with the emotional responses that cause them to be amenable to allowing a man to obtain the sexual release that penetrating her body can provide. A woman interprets a man’s admiration and devotion as romance.
I came to realise that a woman leaves the initiative to a man because she has no agenda of her own. Women refer to sexual arousal with a lover but these are emotional feelings. [i] They do not result from a mental focus on eroticism. A woman has many diffuse feelings in anticipation of intercourse but these sensations come from the mind and body preparing to accept an act of penetration, which is the most intimate act we can ever engage in. This is why women cannot explain erotic turn-ons with a lover.
[i] There is, it seems to me, an erotic continuum, of which orgasm is merely one point, one period, more intense, but qualitatively not different from the experience immediately preceding and following. (Shere Hite)
Excerpt from Understanding Sexual Response (ISBN 978-0956-894762)