It’s been known for some time that lefties and the ambidextrous are more prone to negative emotions. The new study shows that they also have a greater imbalance in activity between the left and right brains when they process emotions. Of course, you can’t be sure which comes first: maybe angry people are more out of balance, or maybe the inability to find equilibrium makes you angry. As for the left-handed: maybe they’re more angry because the world is designed for the right-handed majority.

The study also used an interesting method to find that angry people are, literally, hot-headed: the authors of the paper — led by Ruth Propper, a psychology professor at Merrimack College in Massachusetts — measured brain-hemisphere activation with a relatively old method called tympanic membrane temperature, which is essentially how hot it is in your inner ear. If you get angry a lot, your head tends to be warmer.