The question hanging over Michael Cohen’s congressional testimony is: Can a convicted liar tell the truth?

Cohen, President Donald Trump’s former personal lawyer and ‘fixer,’ testified Wednesday before the House Oversight and Reform Committee about alleged wrongdoing by his former employer. Trump’s Congressional supporters at the hearing repeatedly questioned whether anything said by Cohen, who will soon start a three-year sentence in federal prison for crimes he committed while working for Trump—including lying to Congress—can be trusted.

So, can it?

“It’s so hard to know,” says Laura Dudley, a behavioral analyst at Northeastern University. But, she adds, there is one largely agreed-upon behavioral “tell” when someone is lying, and she didn’t see it in Cohen.

“One of the tell-tale signs that someone is lying is if they demonstrate a dramatic change in their behavior after you’ve asked them a question point-blank,” says Dudley, who is also a clinical professor at the university who specializes in body language. “I didn’t see a big nonverbal reaction like that from Cohen in response to a question.”

On the other hand, Cohen’s known history of lying, coupled with the public speaking skills he’s developed from a career as a lawyer with high-profile clients, makes reading his body language especially challenging, Dudley says.

“People can control their behavior, particularly people like Michael Cohen, who are seasoned public speakers,” she says.

Cohen on Thursday was back in front of the committee for another day of sworn testimony behind closed doors, the last of three days of hearings held so legislators could investigate potential wrongdoing by the president and those in his inner circle.

Dudley has also analyzed the body language of former FBI Director James Comey, Supreme Court Justice Brett Kavanaugh and his accuser Christine Blasey Ford, and both Trump and House Speaker Nancy Pelosi from two different State of the Union Addresses. She says Cohen stands out because he wasn’t trying to stake his claim “on having a respectable reputation.”

But she cautions that body language analysis isn’t an exact science, because it’s impossible to divine a person’s private thoughts with 100 percent certainty.

Even the controlled way with which Cohen answered questions—not displaying a “big nonverbal response” to them—could be explained by his experience in the public arena.

There were other moments that stood out to her.

Wednesday’s testimony was more than nine hours long, and while Cohen seemed nervous in the beginning—his fingers were fidgeting, his eyes were often darting around the room, he was visibly swallowing, and he frequently looked down at the papers in front of him on the table—his voice belied none of that nervousness, Dudley says.

“A stressful situation, or even merely anticipating a stressful situation, elicits a fear response that includes sweating, darting eyes, excessive swallowing or blinking, stiff posture, etc.,” Dudley says. “Over time, though, a person begins to habituate to the situation, and that fear response begins to dissipate. That’s what we saw with Cohen.”

As the hearing went on, Dudley observed Cohen joking and smiling, such as when Rep. Jim Jordan, a Republican from Ohio, asked him about a fake Twitter account created in Cohen’s name.

Jordan pressing Cohen about a fake twitter account "Women for Cohen" pic.twitter.com/bCEYWIerF0

— Washington Examiner (@dcexaminer) February 27, 2019

There were also two moments during Cohen’s opening statement when he “looked directly at the camera and addressed Trump directly,” Dudley says.

“That almost made me stop in my tracks; it was so direct,” she says.

In the end, though, Dudley says she suspects whether you believed Cohen or not depends upon your political bent.

“Trump’s supporters are likely to interpret Cohen’s body language differently than his non-supporters,” she says.

For media inquiries, please contact Shannon Nargi at s.nargi@northeastern.edu or 617-373-5718.