They also bear responsibility for creating a culture where missteps are less likely, the professors said.
"It would have been a home run if he would have said, 'I'm going to go back and interview everyone, and the first person I'm going to interview is myself,' " Portwood said.
The governor denied any role in orchestrating September's traffic tie-ups, blaming the mess on top lieutenants who betrayed his trust, and firing or pushing aside two of them.
"Embarrassed and humiliated," Christie said, describing his feelings. "Incredibly sad and betrayed."
Christie said he fired his deputy chief of staff, Bridget Anne Kelly, for lying to him.
And his campaign manager, Bill Stepien, was asked to step away from a bid to lead the New Jersey GOP because, Christie said, he no longer trusted his judgment.
But it is Christie's judgment that may be called into question for failing to manage his inner circle, the professors said.
"You don't have an inner circle if you don't trust, and have the trust, of the people around you," Useem said.
"He has to strengthen how he manages the internal world that he runs," he said, adding that all leaders work through their top management tiers.
"Having great people in those tiers and instilling in them their obligation to report the good news and the bad - that's what leadership is all about."
Area chief executives interviewed in question-and-answer Leadership Agenda profiles published each Monday in The Inquirer are acutely aware of that.
"Knowing that I'm a forceful personality, I want to make sure that the team around me is strong enough to challenge me," Nutrisystem Inc. CEO Dawn Zier said in her interview.
"I do listen," she said, "but I don't want to just be 'yes-sed.' You need to redirect me if you think I should be redirected."
Maybe, the professors speculated, Christie's forceful personality deterred his top lieutenants from telling him all they knew about the scandal.
"I think he has to ask this question: 'Does my demeanor, how I handle certain situations, send a [wrong] message about what constitutes legitimate behavior?' " Portwood said.
"It's human nature not to take bad news up" to the boss, Useem said. "The art of leading is to recognize human tendencies and to do something about it."
To encourage "bad news" from underlings, leaders should:
Directly assign top lieutenants to be naysayers.
Praise bearers of bad tidings.
Hold informal private meetings further down the ranks to gain a fresh perspective.
In a meeting, ask lowest-ranked employees to speak first so they don't just echo their bosses.
SOURCE: Michael Useem, University of Pennsylvania