Tone and body language at the Harris-Trump debate speak as loudly as words

As their high-stakes debate in Philadelphia commenced on Tuesday night, Vice President Kamala Harris walked across the stage, maneuvered around a lectern and stuck out her hand in greeting.

“Kamala Harris,” she said to former President Donald Trump by way of introduction.

Meeting him for the first time in person, Harris forced her opponent to shake hands, something he and her predecessor as the Democratic presidential nominee, Joe Biden, did not do in June.

It was one of many moments at the debate in which the two candidates used body language, tone and demeanor instead of talking points or policy positions to do battle.

“It was a power move,” said body language expert Mark Bowden, referring to Harris’ pursuit of Trump for a handshake. “I don’t think he was expecting that.”

The vice president maintained an expressive face throughout the evening, raising her eyebrows, laughing, and looking on as if in disbelief as Trump spoke, moments that were quickly snapped and recirculated by her fans on social media. At times she looked at the Republican nominee quizzically and remarked that his comments were “not true.”

Trump mostly kept a serious expression on his face, while sometimes smiling with pursed lips or shaking his head. He accused Harris of mistruths as well. “There she goes again. It’s a lie,” he said at one point.

Throughout the debate, both candidates raised their voices. Harris, 59, frequently turned towards her opponent as she spoke, at one point appearing to scold him. Trump, 78, mostly looked straight ahead.

“Their approaches were very different,” said behavioral scientist Abbie Marono. “He didn’t address her; he didn’t orientate toward her when he was speaking … She was a little antagonistic towards him, but she was also very emotionally responsive towards him.”

Trump’s aggressive style has helped and hurt him on debate stages. His personal attacks during the 2016 Republican primary and the general election against Hillary Clinton propelled him to the nomination and the presidency.

But a 2020 debate against then former Vice President Biden, during which Trump interrupted repeatedly, backfired, turning off exhausted viewers.

On Tuesday night, Trump limited his personal attacks on Harris, aiming primarily at her policies. But he continued attacks against Biden, prompting Harris to underscore that she was now his opponent.