Goku’s hair doesn’t all go straight up like that except when he’s Super Saiyan, and when he is Super Saiyan, his hair is wider/longer than that. Also, you can see Gohan’s characteristic hair curl at the front of his head.

Basically, hair looks like Goku’s SSJ hair but black and significantly shorter, and a curl at the front of the head. This is 100% Gohan.

That’s Gohan, not Goku. Still no chance of Tien doing that to him, of course.

That’s Gohan. Tien still wouldn’t stand a chance though.