Sex at Dawn полностью

If our paradigm of prehistoric human sexuality is correct, in addition to environmental toxins and food additives, sexual monogamy may be a significant factor in the contemporary infertility crisis. Widespread monogamy may also help explain why, despite our promiscuous past, the testicles of contemporary Homo sapiens are smaller than those of chimps and bonobos and, as indicated by our excess sperm-production capacity, than those of our own ancestors.

Sexual monogamy itself may be shrinking men’s balls.

Perhaps we can declare an end to the standoff between those who argue that small human testicles tell “a story of romance

and bonding between the sexes going back a long time, perhaps to the beginning of our lineage,” and those who contend that our

slightly-larger-than-they-should-be-if-we’re-really-monogamous testicles indicate many millennia of “mild polygyny.” Humans have medium-size testicles by primate standards—with strong indications of recent dwindling—but can still produce ejaculates teeming with hundreds of millions of spermatozoa. Along with a penis adapted to sperm competition, human testicles strongly suggest ancestral females had multiple lovers within a menstrual cycle. Human testicles are the equivalent of drying apples on a November tree—shrinking reminders of days gone by.

As a way of testing this hypothesis, we should find that relative penis and testicle data differ among racial and cultural groups. These differences—theoretically due to significant and consistent differences in the intensity of sperm competition in recent historical times—are what we do find, if we dare to look.¹³

Because fit is so important in the effectiveness of condoms, World Health Organization guidelines specify different sizes for various parts of the world: a 49-millimeter-width condom for Asia, a 52-millimeter width for North America and Europe, and a 53-millimeter width for Africa (all condoms are longer than most men will ever need). The condoms manufactured in China for their domestic market are 49 millimeters wide. According to a study conducted by the Indian Council of Medical Research, high levels of slippage and failure are due to a bad fit between many Indian men and the international standards used in condom manufacture.¹⁴

According to an article published in Nature, Japanese and

Chinese men’s testicles tend to be smaller than those of

Caucasian men, on average. The authors of the study

concluded that “differences in body size make only a slight