Every SpongeBob SquarePants episode starts with the voice of an old sea captain shouting, “Are you ready, kids?” to a chorus of children who reply “Aye, aye, captain!” As wholesome and fun as this show is, though, recent research shows that younger children might not be ready for SpongeBob after all.

When parents think of what makes a TV show suitable for children, they focus on content. Is there violence, vulgarity, or other inappropriate content?

These concerns connect with how we think children learn. Seeing violence might encourage children to act more violently. If a lead character on a show uses rude language, is unfriendly or otherwise acts with poor manners, we worry that our own children may come to see that behavior as acceptable for themselves.

It was with these traditional concerns in mind that, some years ago, my wife and I sat down with our young children to watch an episode of SpongeBob SquarePants. We saw nothing objectionable. SpongeBob himself is a naive, caring, overachieving character who takes pride in his work and delights in playing with his best friend — the dimmer, underachieving Patrick.

The humour is occasionally crude, but this did not bother us, particularly given that crude humour is usually in evidence around our dinner table. In all, we found SpongeBob to be generally wholesome and fun and laughed with our kids as we watched.

Thus, it was with fascination and alarm that I learned this week of a study conducted by colleagues of mine from the University of Virginia. Their study showed that immediately after watching an episode of the wholesome SpongeBob — just nine minutes long — preschool children were more impulsive, and had more difficulty following rules and making plans.

This was compared with preschoolers who watched nine minutes of another children’s show, Caillou, and preschoolers who watched no TV but drew pictures for nine minutes.

There were no differences between the Caillou group and the drawing group, which showed that poor performance was not due to watching TV generally. Rather, there’s just something about watching SpongeBob that affects children’s cognitive performance.

From a scientific perspective, the study was beautifully done. Children were randomly assigned to the experimental conditions and the researchers took pains to ensure that the findings were not attributable to experimenter bias. Also, the observed effects in the children were remarkably large — reminiscent of what happens to cognitive performance in adults after sleep deprivation or a few alcoholic drinks. In short, I don’t see any way to seriously debunk the scientific merit of the study.

So, why does a show as essentially wholesome as SpongeBob have such a strong acute effect on preschoolers’ immediate cognitive performance? The researchers don’t know, and their study wasn’t designed to test any specific hypotheses. However, the researchers suspect that the most likely culprit is the fast pace of the show.

Quick editing has become so commonplace in mainstream media that adults barely notice. Thus, my wife and I may not have thought twice about the fact that when watching SpongeBob, there is, on average, a complete scene change every 11 seconds, compared to 34 seconds in Caillou.

From preschool children’s perspective, this fast pace might cause problems for two reasons.

In preschool-aged children, the cognitive skills that the researchers were testing are somewhat immature and developing rapidly. It’s possible that fast-paced shows might be overly taxing given preschoolers’ weaker cognitive abilities. After watching SpongeBob, young children might be cognitively tired and then, when they are asked to do something else, the resources simply aren’t there.

If this is true, then we might not expect the acute effects of watching SpongeBob to be the same for older children who are generally more cognitively capable.

A second possibility is that seeing something new every 11 seconds causes children to develop a cognitive pattern whereby they are more stimulus-bound — tending to attend most strongly to information that is immediately at hand and less able to focus on abstract rules, longer-term plans and goals that have to be kept in mind while other things are happening.

If this explanation is correct, children of all ages might be at some risk for acute cognitive difficulties after watching fast-paced TV shows. For younger, less-able children, the consequences might be more obvious and severe.

If the researchers are right, parents have something else to think about when figuring out whether a TV program is suitable for their children.

Besides the content, parents might also want to consider the form of the show and avoid letting children watch fast-paced shows particularly just before they have to engage in high-level cognitive activity.

Obviously, school is a place in which cognitive skills, like following rules and keeping goals in mind, are critical for success. More relevant for preschoolers, many everyday activities around the house require the ability to follow rules and keep goals in mind — getting out the door in the morning is one that comes quickly to mind, and for many families can be a struggle.

Colleagues have been asking me whether I let my kids watch SpongeBob. Whereas before I would have given an enthusiastic “Aye, aye, captain!” and regaled them with the whole theme song, I am now more thoughtful. For older children, there might be a time and a place for SpongeBob, but younger children might not be truly ready to answer the captain’s call.

Mark Sabbagh is a professor in the Queen’s department of psychology.