So you want a girl?

摘要

Parents have been trying to choose the sex of their children for as long as they've been having them. In ancient Greece, Aristotle counseled men to tie off their left testicle to guaranrtee guarantee a son. The Talmud advises fiusbands to hold back and let wives take their pleasure first if they want boys. In late. 20th-century America, an obstetrician named Landrum B. Shettles built a near-cult following for a best-selling book that advised timing sex to ovulation: several days before if you want a girl, at or near the event for a boy. None of these, nor a thousand other recipes that humans have cooked up over the ages, have been proved scientifically. That's another way of saying that, at least in the eyes of the medical establishment, they just don't work.