Is he eating ok? As long as he has a good appetite, he's probably doing just fine. A lot of devils don't get their characteristic aggressive attitude until larger.
Does he have a hiding spot? What size is his tank? Also, bright lights can make a devil shy.
Your devil will eventually grow out of that stage. Wait until he hits about the 6" mark. That's when mine began to show his dominance and agression. As long as he is healthy and eating, as previously stated everything should be fine.
Yup, he's eating alright, don't have a problem with his appetite. he has a big pvc t-pipe joint for his house, and he rarely goes out of his house, asides from eating time.
He may and may not snap out of it, depends on his personality. I had 2 wc midas and the first one got spooked so easily, while the second one was a glass banger. I'm pretty sure if you get him a female and they spawn, he won't be shy anymore. Good luck with your new guy.