According to The Science of Us (and leaving aside the well known issues related to our excessive consumption of the stuff) 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.”