"We expected that differences in family income, parental education, and sources of information would explain the racial disparities in age-appropriate restraint use and they did not," lead author Dr. Michelle L. Macy told Reuters Health by email.
Certain parents may face barriers to car seat and booster seat use that researchers haven't discovered yet, Macy, a pediatrician at the University of Michigan in Ann Arbor, said. Or social norms could explain the differences between racial groups.
The new study took place in Michigan, where state law requires that children under four use a car seat and kids four to seven use a car seat or booster seat unless they are taller than 4 feet, 9 inches.
Experts generally recommend older kids under that height keep using a booster seat as well. The Centers for Disease Control and Prevention says all kids under 13 should ride only in the back seat.
The new study was based on surveys of 600 parents of kids ages one to 12.
Close to 3 percent of kids under age four ever sat in the front seat, compared to 10 percent of kids ages four to seven and 34 percent of kids ages eight to 12, according to findings published in Pediatrics.
Among four- to seven-year-olds, twice as many non-white kids sat in the front seat as white kids. For the other age groups, there was no difference based on race.
Across the board, white parents were between three and four times more likely to report using age-appropriate seats for their children than non-white parents.
Parents' education and income didn't explain the racial differences in seat use, and all parents got their child safety information from similar sources.
Parents most often learned to use car seats by reading the instruction manual or "just figuring it out." They sought child car safety information from friends, family, doctors or nurses. The most common source of information was the Internet, which was used more often by white parents.
Image: Baby in car seat, via Shutterstock