Accidents are the No. 1 killer of American children, and car accidents are the most common kind of lethal accidents. It makes sense that health officials focus on making car accidents less common and less dangerous.

Unfortunately, as with many other areas, regulations often don’t fully line up with research.

In 2011, the American Academy of Pediatrics (A.A.P.) released a policy statement on car safety that recommended that children ride in rear-facing car seats until at least age 2. Before that, the recommendation was until 1. This change caused something of an internet firestorm.

It’s not terribly hard to get small babies into an American-style rear-facing car seat, but those who are nearly 2 years old are a different story. They often resist. They can fight. It can be miserable for both parties.

The authors of the A.A.P. guideline seemed on solid ground. They relied heavily on a 2007 study in the journal Injury Prevention that extracted data from the National Highway Traffic Safety Administration’s car crash database from 1988 through 2003. They found that children from newborn to 23 months who were restrained in a front-facing car seat were 76 percent more likely to be seriously injured than children in a rear-facing seat. In side crashes, serious injury was four and a half times more likely.