For thousands of years, babies slept with their mothers. When they cried, they were attended to. Then two men came along: Dr. Holt and John B. Watson. They said babies should be trained. That babies had to fit the assembly line schedules of their parents. "Newborns must cry to expand their lungs," they claimed. "Simply let them cry it out." And that's how the "cry it out" sleep training method was born. Watson treated babies like experiments. "Never hug or kiss your child," he wrote. "Shake hands with them in the morning." After all, mothers needed rest, to attend to their husbands and households. Watson had four children. Three attempted suicide. One succeeded. And we still follow it today. Because once you convince a mother to ignore her baby's cries, you've broken something primal.