Common Myths of Children's Behavior

A number of false beliefs about children's behavior are very common among parents and the lay public. This article summarizes scientific findings and applies critical thinking to show what's tripped up so many of us.

No one considers parenting a pseudoscience, but many of the "truths" that parents believe are contradicted by scientific knowledge. Discussion of these myths can shed light on our knowledge of children's behavior: In addition, the discussion illustrates some basic scientific principles that can also be applied elsewhere.

1. "Don't give Sheldon that candy--sugar makes him so hyper!" Many parents and teachers report that childrens' consumption of sugar results in hyperactivity. But the empirical research is clear: consumption of sugar has no effect on children's behavior as rated by objective observers (Milich, Wolraich, and Lindgren 1986). So why are parents and teachers convinced it has such devastating effects? They are not aware of the need to control for covariates. A covariate is another variable that is associated with the variable of interest, in this case sugar consumption, but that might not be as noticeable. What variables might be overlooked by parents and teachers in judging the effects of sugar? Well, think about the situations in which children eat a lot of sugar, like birthday parties and Halloween--these are situations that are likely to excite children.

There's another possible covariate, too. Children whose parents don't restrict sugar at all, letting their children eat whatever they want whenever they want it, are also more likely to let their children run wild in other ways. And parents who restrict sugar (it is bad for your teeth, after all) are also more likely to teach self-restraint and obedience. But we often see the child without seeing the parenting. So we see an association between the sugar and the behavior, instead of an association between parenting style and behavior.

2. "She's writing her letters backward--it must be dyslexia." Many parents and teachers become concerned when a child is reversing letters, afraid that this is a sign of dyslexia. But the empirical research indicates that the primary indicator of reading disabilities such as dyslexia is difficulty with auditory processing and phonemic awareness--breaking words down into their component sounds (Beitchman and Young 1997; Shaywitz 1996). Dyslexia isn't a visual disability at all, but an auditory one. Parents and teachers should be concerned about a child who can't generate rhyming words, not one who is reversing letters.

So why are people so concerned about reversals? They are not aware of the effect of base rate in interpreting behavior. The base rate is the percentage of the general population that has a given characteristic. In this case, all children start out making reversals. After all, letters and numbers are the only things that we draw where the direction the figure is facing makes a difference in its name. (A dog facing right instead of left is still a dog; a 'd' facing right instead of left is now a 'b'.) Children gradually learn which way the letters face and by second or third grade they are no longer making reversals. The same percentage of children make reversals, whether they are having difficulty with reading or not (Black 1973; Pemberton et al. 1993), although children with reading disabilities may keep it up a little longer. But people only notice with the kids who are having trouble--and never compare it to the base rate.

3. "Tanisha is just immature. If we have her repeat first grade, she'll do better in school." Many parents and teachers are convinced that some children are too young or too immature for their grade placement, and that retention will help them catch up. But the empirical research indicates the opposite--retention not only has no long-term benefits, it can actually harm children emotionally (Jimerson, et al. 1997). In fact, children rate retention as the third most horrible thing they can imagine happening to them--after losing a parent and going blind (Yamamoto, et al. 1987). So why are parents and teachers convinced that it is helpful? Lack of long-term followup and lack of a control group. In most cases, a teacher judges the outcome of retention the next year, when the child is actually repeating the same grade. At that point, the child may be doing well academically. But the following year, when the child starts to fall behind again, the teacher isn't following up any more. And the parent says, "Well, the retention helped for a while, but now we need to try something else." And without a comparison to children who weren't retained, it's hard to see the benefits of promotion--and the costs of retention.

4. "Praise doesn't work. After I compliment John, his performance goes downhill. It's yelling whenever he messes up that really gets results!" Many parents and teachers are convinced that punishment is more effective in changing behavior than praise. But the empirical research indicates that positive reinforcement is more effective than punishment in changing behavior and especially in teaching new skills (Alberto and Troutman 1999). So why are parents and teachers convinced that punishment is better? They aren't familiar with the statistical concept of regression to the mean. When you are first learning something, there is a large element of random chance in how good your performance will be. Statistically, this random variation causes an interesting effect. After a particularly good performance, the chances are the next one will be worse, no matter what happens. And after a particularly bad one, the chances are the next one will be better, no matter what happens. So it looks like the praise caused your perf ormance to deteriorate, and the yelling caused you to do better. But really, it was just random variation bringing you closer to the average. (For more on the regression effect, see "Superstition and the Regression Effect," by Kruger, Savitsky, and Gilovich, SI 23[2] March/April 1999.)