Man, if your kids hear this, prepare for this to be Exhibit A when they make their case to get iPhones.

According to a new study, kids who have smartphones acually study approximately 40 minutes more per week than kids who don't. And yes, it's because they use their phones to study.

Kids with smartphones were most likely to get in extra studying on their way to school, or just before going to bed. Also, 19% used their phones to study in the bathroom.

But, researchers also found there was no correlation between that extra studying and higher grades. So while a smartphone leads to more studying, that didn't necessarily translate to better test scores.