Updated

CHICAGO -- A study on grandparent drivers has its researchers doing a double-take over the results.

The study found that kids may be safer in cars with grandma or grandpa at the wheel instead of mom or dad.

The results are from an analysis of State Farm insurance claims for 2003-07 car crashes in 15 states, and interviews with the drivers.

Overall, 1.05 percent of kids were injured when riding with parents, versus 0.70 percent of those riding with grandparents, or a 33 percent lower risk. The difference was even more pronounced -- 50 percent -- when the researchers took into account other things that could influence injury rates, including not using car seats, and older-model cars.

The findings fly in the face of previous evidence that car crashes are more common in older drivers, mostly those beyond age 65.

Researchers speculate that grandparents are extra-cautious when tasked with driving their grandchildren.

The study is published in the journal Pediatrics.