There are a couple of things at work here. 1) Some people choose to spend their time on learning and improving their brains, instead of their outward appearanc

There are a couple of things at work here. 1) Some people choose to spend their time on learning and improving their brains, instead of their outward appearances. Over time, this makes them smarter than those who don't. 2) In most societies, good-looking people often have it easier; as a result, if you're not good-looking, you have to work harder. Which, in turn, makes you smarter over time.