The truth is out: men and women are both from Earth! They evolved together, but differently, to have different brains, bodies, and behaviors. And now, at last, we can all understand how, and why, and what this means for each of us. Everyone - religious leaders, politicians, obstetricians, moralists, educators, poets, musicians, artists - has something to say about sex. But it is biology that enables us to make sense of sex, and of sex differences. (The book is "MAKING SENSE OF SEX: how genes and gender influence our relationships," by David P. Barash Ph.D. and Judith Eve Lipton MD.)

Sex differences R us. They stimulate our social lives, they underlie the joys and frustrations of being human. Maybe it doesn’t sound terribly romantic, but fundamentally the differences between men and women are a matter of eggs and sperm: For billions of years, egg makers have diverged from sperm makers, each attempting to make more successful offspring. Each sex requires the other in order to succeed, but their strategies and requirements are quite different. Hence, conflict is as natural as cooperation, and as inevitable. Sexual delights and sexual torments, child-bearing and child-rearing, the tensions and the joys of daily life—all are fueled by the nature of sex itself. By understanding this, you can finally make sense of sex and of yourself. In addition, you can change and improve your social relationships, and take charge of your life.

Why do men want sex more than women do? Why are men more likely to be promiscuous than women are? Why are prominent, successful, and powerful men especially attractive to women (and could this have anything to do with Bill Clinton)? Why are women more inclined to care for infants? Why are men more violent and women, more verbal? What about rape? Can we learn anything from homosexuality? Why don’t men lactate? Why do women have prominent breasts (and why do men like them)? Why do women undergo menopause, and why don’t they experience "heat" like most other mammals? Why are men more stimulated than women by the prospect of sex with a new partner? Why do men visit prostitutes and view pornography (and why don’t women)? Why do women become sexually mature earlier than men, and live longer? What do men seek in women, and what do women seek in men? Is monogamy "natural"? Is adultery? What about male-female differences in thinking, and the role of hormones? Do sex differences show up early in childhood, and what are they like? These are only some of the questions to be answered when we make sense of sex ... and Barash and Lipton’s book help the reader to do just that.