Like the spirited Lucille Ball, redheads are known for their fiery passion. But can they really feel more intensely?

Researchers have long known that variants in a certain gene—the melanocortin-1 receptor (MC1R) gene—are what cause red hair. That gene may also make redheads more pain sensitive than others, and more resistant to pain killers—a downside that impacts health behavior.

This study surveyed 144 people (67 redheads and 77 brunettes), and found that redheads, who are resistant to local anesthetics, report more anxiety and fear about the dentist. They’re also more than twice as likely to avoid dental care altogether.

Looks like redheads tread more gingerly (pun intended) than the rest of us.