One-sided eyebrow raising is not necessarily innate, it is basically acquired.

To raise eyebrows, you need to use the muscle tissue near the eyebrows to drive the eyebrows. This is generally natural. But making an effort to exercise the muscles near your eyebrows can also improve it.

Some people can move a little after practicing, and some people can move only one.

The main function of eyebrows is to prevent water from flowing into the eyes. The curved shape of the eyebrow edge and the direction of the brow tip can ensure that water droplets flow along the sides of the face and up the nose without flowing into the eyes. The slightly protruding eyebrow arch of humans in the 21st century still plays a supporting role in this function.