In my favorite of these studies, children were divided into two groups. All of them were given a sugar-free beverage to drink. But half the parents were told that their child had just had a drink with sugar. Then, all of the parents were told to grade their children’s behavior. Not surprisingly, the parents of children who thought their children had drunk a ton of sugar rated their children as significantly more hyperactive. This myth is entirely in parents’ heads. We see it because we believe it.