If you give a mouse a cookie, as the children’s book goes, it will ask for a glass of milk. If you give a small child a cookie, as the conventional parenting wisdom goes, it will turn into a wild-eyed, wall-climbing monster, fearsome and uncontrollable until the sugar high has tapered off.
Except as writer Laura Geggel explained yesterday on Live Science, that second statement, like the first, is more a good story than anything else. The concept of the sugar high is something of a parenting urban legend; plenty of research has shown that feeding kids sugar doesn’t make them hyper. What it does do, though, is prime their parents to look for signs of misbehavior.
In part, pediatric researcher Mark Wolraich told Geggel, the misconception stems from the fact that sugar often marks a special occasion: When kids are stuffing themselves with birthday cake or Halloween candy, they’re already in a situation where they’re going to be naturally amped up. But “[parents’] ideas are reinforced by seeing it in those circumstances,” Wolraich said. “The placebo effect can be very powerful.”
Research backs him up: In one 1994 study in the Journal of Abnormal Child Psychology, researchers recruited 35 boys between the ages of 5 and 7 whose mothers had reported them to be “sugar-sensitive.” All 35 kids were given a placebo, but half the mothers of the study subjects were told their kid had actually taken a dose of sugar. When the study authors released the boys back to their parents for some supervised playtime, the moms who believed they were dealing with a sugar-crazed kid “rated their children as significantly more hyperactive,” the researchers wrote. They were also more likely to treat their sons like they were misbehaving, “showing trends to criticize, look at, and talk to their sons more than did control mothers.”
That same year, Wolraich led a separate study that placed 48 kids on a strict diet high in either sugar or artificial sweeteners, and asked parents to keep a log of their kids’ behavior. At the end of the study period, the researchers concluded — based on the parents’ journals, teacher reports, cognitive and behavioral tests, and their own observations — neither diet made kids any less sharp or less well-behaved than usual. (In fact, they wrote, “the few differences [in the sugar diet] were more consistent with a slight calming effect than with hyperactivity.”)
Both experiments were based on small samples, but a 1995 meta-analysis of 23 studies, also led by Wolraich, reached a similar conclusion. “Sugar does not affect the behavior or cognitive performance of children,” the researchers wrote, and “the strong belief of parents may be due to expectancy and common association.” In other words: A kid’s sugar-addled brain is just a projection from a parent’s worried one. There’s already plenty of justified hand-wringing about sugar intake — here, at least, is a reason to be calm.