The XX Factor

If Crying It Out Causes Brain Damage, We All Need Treatment

“Every time your baby cries, and you don’t respond, you break the fragile bond of trust between you.” That’s the way I remember a line from a Dr. Sears book that sat on my bedside table when both my first and second kids were infants. Those are the words I remember echoing through my head every time Sam or Lily wailed and I did not or could not go to them, either because I was with the other kid or in the shower or because (and this happened often) it was the 20 th time in an hourlong “nap” and I just couldn’t .

That was at least six years ago. Today’s parents got an even more scientific jolt of guilt with their news recently, when psychologist Penelope Leach (whose book Your Baby and Child was right under that Dr. Sears volume, and who’s currently promoting a new book, The Essential First Year ) was quoted in many papers as saying that when a baby cries hard and no one responds, “the brain chemical system releases cortisol and that is very bad for brain development. Some neuroscientists describe it as toxic.” Now there’s a line that resonates. British psychologist Oliver James reached a similar conclusion about a study showing that 15-month-old children placed in day care had elevated levels of cortisone: “When cortisol is measured at age 15, the longer a child was in daycare when small, the higher its levels. As high cortisol has been shown many times to be a correlate of all manner of problems, this is bad news.”

Both Leach and James are relying on the same assumption: that high levels of cortisol are a bad thing. But that’s far from proven, as both the Neuroskeptic blog and Vaughan, writing at Mind Hacks , note. For one thing, things that raise cortisol levels by small amounts, like those shown in the study cited by James, include breast-feeding, tooth-brushing, and nearly every physical activity. Mind Hacks also links to studies showing that increased cortisol levels were related to better mental performance in young children. In other words, the effects of cortisol are far from black-and-white, and probably not yet perfectly understood. But that makes a lousy headline.

And it’s the headlines and the easy takeaways that stick with sleep-deprived, anxious parents. Once my two youngest were out of the baby stage, I went back to that Dr. Sears book, looking for the line that had caused me so much anguish. I couldn’t find it. Eventually, I found the “lack of trust” reference in an aside by Sears’ wife, Martha, responding to an anecdote from a mother who felt her child rejected her after she let the baby cry for a night. I’d built an entire castle of worry out of one throwaway comment. Imagine what I’d have done (and what plenty of other mothers must be doing) with a real, apparently research-based, headline.

Mind Hacker Vaughan notes that his “bullshit switch” is triggered when he reads phrases like “neuroplasticity” and “raises cortisol,” but mine isn’t nearly so carefully wired. I take anything that includes the words “recent studies show” with a grain of salt until I’ve clicked on the link and read the actual study. But few new parents have time for that kind of thing. Probably the best thing for a young mother like me would have been to stick to rereading Pride and Prejudice until the fog cleared.