Adam Parrish canonically gets dry and cracked skin on his hands, probably enough for it to bleed. He would have heard a hundred times about how it looks like he's been in a fight, a joke that never gets funnier every time he hears it. Adam "Do you think it makes me look tougher?" Parrish. Adam, who goes to punch the wall and just presses his hand against it. Who is terrified of becoming his father.
And, despite all that, still has cracked and bleeding knuckles, without needing to hit a thing. As though, no matter how hard he tried to avoid it, the capacity to hurt was written into his skin- inherited.