A right-handed friend in high school was so worried about breaking her right hand — thus leaving her incapable of taking high-quality notes — that she would practice writing with her left hand just so she could be prepared. But children whose dominant side seems to vary naturally? They concern researchers.

A new analysis has found that children who are "mixed-handed," or "cross-dominant," that is they do some tasks better with one hand, other tasks better with the other hand, are more likely to have language, learning and mental health problems, including attention-deficit hyperactivity disorder symptoms, at least compared with right-handed children.

That's the word from a long, large study from Finland published Monday in the journal Pediatrics.

The researchers conclude that mixed-handedness, which indicates the brain is wired a little differently than is the norm, could be used to help identify children at risk of such problems.

But, please, no one's suggesting that children be forced to use one hand or the other — the treatment some lefties once endured before the rest of society got enlightened. For now, it's just one more thing about which easily unnerved parents can fret.

There's more on handedness and brain lateralization from Indiana University, and a self-test known as the Edinburgh Handedness Inventory.

As for that high school friend, I opted to be impressed with her diligence. Perhaps a little unnerved, yes, but also impressed.