Beyond keeping hair out of your eyes or providing easy access to your brain’s escape hatch, the way you part your hair can reflect how the world perceives you—and how you perceive yourself. How to part it depends largely on the shape of your face. Here are a few basic guidelines to finding the right method:

Heart: With their wider cheekbones and glowing foreheads, heart-shaped faces radiate with either a side or diagonal part. However, if you have longer hair, a middle part may help to balance out your prominent cheeks.

Square: The trick with a square-shaped face is to soften its features. A deep-side part or diagonal part allows hair to fall gently over any sharp angles, rounding them out. In this case, it’s best to begin the part right above the arch of one eyebrow.

Circle: A slightly diagonal part that stretches from the middle of the forehead to the back of the hair lends a dramatic curtain effect to circle-shaped faces, enhancing and elongating the features on the side with the greater exposure.

Oval: Oval-shaped faces have it toughest of all, since they’re doomed to be able to pull off any look they want. The choices are virtually infinite. Part it down the middle or down either side. Don’t part it at all. Part it six times—the world is your oyster cracker. However, many stylists would recommend a middle part, since side parts already suit the shapes above.

The decision of where to part the hair, however, isn’t completely cosmetic. Some people theorize, for example, that a left part indicates someone with strong leadership skills. This theory earned some cred during the 2000 US presidential election, when left-parting George W. Bush defeated right-parting Al Gore. Even comic books lend it some credence, as the unassuming Clark Kent switches his part from the right to the left when he becomes the all-powerful Superman. Still, it could be just a coincidence—many successful leaders part their hair on the right or not at all, and either way, the decision is not always up for debate; a cowlick, for instance, is nearly impossible to tame, often forcing you to adapt your style to suit it. Our perception of ourselves is inherently flawed. Therefore, if you like the way your hair looks parted to the left, you may want to actually part it to the right, even—and perhaps especially—if it looks strange in the mirror.