I've always been under the assumption that when a guy has pectorals that make his nipples point towards the ground, it's because he's has too much lower pectoral development. And that the square chest look was a sign of very balanced work between the upper and outer chest.
But then, studies like this:
would assert that the pectoral is hit the same no matter what angle you choose
Is it just a case of genetics then? Or is this study shortsighted?