Recently, a friend sent me a 2006 clip from "The Oprah Winfrey Show" featuring a room of fussy newborns and a woman who claimed she could translate their cries. I'm a skeptic by nature, but around March 4, I will have a newborn of my own, and this clip seems to have become required viewing for pregnant women, so I watched intently. Young babies speak five universal "words," Priscilla Dunstan told an enthusiastic Oprah, and I nodded, suppressing if not entirely suspending disbelief—until the show more or less became an infomercial for the "Dunstan Baby Language" DVD. I didn't want to condemn Dunstan's ideas in haste; some of them sounded reasonable. But if they were the real deal, I thought, they'd be mentioned—if not by name, at least by concept—in pediatrics journals. If they weren't, with a bit of searching I'd find they had been debunked.

Three hours of searching and one query to Dunstan later, I had a problem: there wasn't proof either way. The Dunstan company had developed a clinical trial plan with researchers at Brown University, but abandoned it for consumer surveys and small-group observations "to hasten the development of a system that could be used by parents." In other words, it skipped rigorous testing and went straight to market. This was not high-level evidence. I wanted science, truth: a large, randomized, well-controlled trial. Instead, I was going to have to fall back on something I'd made a point of never trusting: my intuition.

If this is how I fare with advice for parents of healthy children, how am I going to make medical decisions for my child when the evidence isn't clear? I've written about parents who have made tough choices under extreme uncertainty: people who put their children on psychiatric meds or enrolled their kids in experimental protocols that might help them but also might harm them. They did it, they told me, by relying on their instincts. They had to. In pregnancy and child rearing, the data about best practices are often murky, even regarding basic matters such as sleeping and feeding.

Yes, doctors are sure of some things: women of childbearing age should take folate; babies should sleep on their backs. But, partly because it's ethically tricky to design trials that involve children and partly because parents are often willing to try anything that may help their kids—no matter how ludicrous it sounds—the answer to many questions about obstetrics, pediatrics and child development is "No one really knows." For all the hype about "evidence-based medicine," there's no such thing as evidence-based parenting—and as someone committed to scientific evidence, I'll admit that scares me.

Thank goodness for Jonah Lehrer's new book, "How We Decide." Like Malcolm Gladwell's "Blink," it argues that sometimes the unconscious is better than the conscious mind at making decisions. "It's like a supercomputer in the brain. It may be better at weighing the variables," Lehrer says. He loves data, but he criticizes the desire to make all decisions based on it, to "be as rational as possible, plug things into some Bayesian theorem, and bada-bing, you've got your answer." He cites experts who agree, and says they often rely on their instincts, too. "We think of experts as people who know a lot of facts," he says. "But actually, many experts are intuitive." From this perspective, the cliché about how "you are the expert on your child" sounds pretty sensible.

After I spoke to Lehrer, I decided not to buy "Dunstan Baby Language." My gut tells me it doesn't work. But I make no promises about what I'll do two months from now when the baby is screaming. My instincts might be different when they're desperately frayed. Let me rephrase that: I might change my unconscious mind. And I'm OK with that.

© 2009