You didn’t need to have the volume on during Sunday night’s presidential debate to know that the atmosphere was throbbing with tension, especially as Donald Trump hovered near Hillary Clinton and made many viewers feel, by proxy, extremely uncomfortable.

The scene of the two discussing Obamacare: Clinton crosses the stage past Trump’s podium to answer a question. Trump then circles behind her and — instead of sitting at his chair — moves forward to stand behind her.

The hover is not the move of a typical politician, Janine Driver, president of the Body Language Institute, told CNN. And it made her, like others commenting on Twitter during the debate, intensely squeamish:

“This is also a pre-assault indicator. So at some parts of watching last night, I was getting really nervous. Because she was in his space; he’s like a dog who’s starting to get anxious. He’s being backed in a corner. So I had a little anxiety during this moment.”

Other body language experts have explained that Trump’s movements are typical of a power-hungry individual. David Givens, director of the Center for Nonverbal Studies, told The Washington Post, “Trump’s constant pacing and restless movements around the state attracted attention from Hillary’s words, and visually disrespected her physical presence on the stage, as in ‘I am big, you are small.’”

Body language expert Robin Kermode tells Broadly that his movements are akin to the same tactics bullies use to make someone cower.

His movements also indicate agitation. Whenever Clinton spoke he would hold his lips tightly together, flick his neck, and thrust his jaw. Kermode says, “This tells me he is not a calm man.”

By choosing to stand in front of Trump, Clinton used her own body language to signal that she would not be intimidated. By making use of his size, direct trunk orientation, upright stance, and possession of space Trump was using age-old signals that signify an attempt at dominance.

Perhaps Trump would have used the same movements on any candidate regardless of gender, but with a history of sexual predation and a looming stance over a woman he’s openly threatened, Trump’s body language conveyed more clearly than anything he actually said last night.

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