Jackson, Jones' longtime head trainer, is fairly certain, however, that "being scared" isn't one of them.
Jones (20-1) is reportedly scheduled to meet with UFC officials this week to discuss terms for his next light heavyweight title defense. The promotion is looking to book Jones to a rematch against Gustafsson, possibly on Aug. 30 in Las Vegas.
On Monday, UFC president Dana White revealed Jones has asked to fight Cormier in his next bout. Jones basically confirmed as much in an Instagram post on Tuesday.
Jones' preference has prompted accusations that he is "ducking" Gustafsson, whom he narrowly defeated via unanimous decision at UFC 165 in September. Jackson doesn't see it that way.
"Everybody is looking for a chink in his armor and they are desperate for it," Jackson told ESPN.com. "They are desperate, like, 'Please let us find something wrong with the guy.'
"I've never heard him say, 'I'll never fight Gustafsson again. I'm scared.' I've never seen that from him at all. I don't really think courage is a problem for Jon Jones. He goes up against the best guys in the division."
As for Jones' reasoning for wanting Cormier (15-0), Jackson speculated it might have something to do with elevating his legacy. Cormier represents a new challenge.
Jones, 26, often talks about leaving a mark in the sport.
"It might be a career move," Jackson said. "He already beat Gustafsson. Maybe he's looking for a challenge and doesn't feel that Gustafsson is the challenge everybody else thinks he is. I honestly don't know, but it could be that Cormier would escalate his greatness more than someone he has already beaten."
A rematch between Jones and Gustafsson (16-2) has seemed inevitable since the first meeting, but according to Jackson, he and Jones have spoken very little about it.
The UFC has taken a hard stance recently that Gustafsson would be next for Jones, but Jackson said he rarely discusses or strategizes for a fight before it's announced.
"That's kind of how a fan would think about the sport," Jackson said. "I'm a fan, too, but I don't have that luxury. If I'm in a camp for [Glover] Teixeira and I'm talking about Gustafsson, that doesn't make any sense. I don't say that, 'This fight is inevitable,' because I don't know. I have no idea. There are things I thought for sure would happen that didn't come to pass and the other way around.
"If we fight Cormier, he's super tough. Gustafsson is super tough. Wherever the coin lands on that, it doesn't really matter to me."