On Monday, Canadian Prime Minister Justin Trudeau visited President Trump at the White House, and there was one moment everyone seemed to be waiting for and reacting to: the handshake.

twitter.com/abc - twitter.com

That's because much has been made of Trump's handshake.

When Trump shook Judge Neil Gorsuch's after announcing his nomination to the Supreme Court, Twitter took note of the vice-like grip and pulling motion the president used when shaking his hand in congratulations.

When Prime Minister Shinzō Abe visited President Trump, a similarly aggressive handshake occurred, with many noting that Prime Minister Abe looked both uncomfortable and also relieved to be done shaking President Trump's hand:

As result of these previous encounters, much was made of Trudeau's swift ability to take control of Trump's signature move:

History tells us there's a lot to learn from the way world leaders shake hands.

The History Channel's 2008 documentary, Secrets of Body Language, explains why. "When body language savvy world leaders get together," the narrator says in the documentary, "they know there's one surefire moment to demonstrate dominance: the handshake photo op."

"If you're looking at the left of the picture," body language expert Janine Driver explains in the documentary, "they always want to be standing on the left of the picture." That's because it looks more dominant. "You've got the upper hand."

Driver points to the famous photo of Elvis Presley meeting with President Richard Nixon in the Oval Office in 1970 as an example of a presidential power move.

Oliver F. Atkins/White House/The National Archives - gwu.edu

"Nixon's got the upper hand — that's where the expression comes from — so now that people know about this in politics, you see them jockeying for the position when it comes time to take the picture."

Which could explain Trump's art of the feel.