When it comes to stirring up widespread xenophobia for political gain, nine out of 10 experts agree that one hugely successful salesman is to blame for the popularity of the tactic – and his name isn't Donald.

Edward Bernays is widely credited with mastering the art of public manipulation, by using a wide range of tactics that play to humans' base instincts and emotional drives. Bernays, the so-called "father of public relations," is credited with a number of impressive and occasionally terrifying accomplishments, including turning bacon into a breakfast food, popularizing smoking among women and toppling a government in Guatemala.

Bernays essentially learned how to dupe society into buying what he wanted them to buy through the use of mass psychology, according to University of Toronto Department of Psychiatry professor Mark Leith.

"He used the expert… to promote bacon," Leith told CTV's Your Morning on Tuesday, as he listed off Bernays's many accomplishments. Leith explained that Bernays would often convince experts or celebrities to endorse the products he was touting, so he could make claims like "nine out of 10 dentists agree, (insert product here) is the best."

Bernays used his uncle Sigmund Freud's theories on psychology to develop a public relations business in the early 1900s, and became a titan in the industry for decades until his death in 1995. In addition to popularizing bacon, Bernays turned smoking into a "feminist issue" with his "Torches of Freedom" campaign for Lucky Strike, Leith said.

"He got secretaries and debutantes to march down the streets of New York and then on cue they all lit up," Leith said. "When that happened, the press around took note."

But Bernays didn't stop his manipulative ways at fattening people up and ruining their lungs. Leith said Bernays is largely responsible for the U.S. executing a coup d'etat in Guatemala in 1954, because Bernays's client, United Fruit, wanted unfettered access to the country's bananas.

"He claimed that the leader (which was not true) was part of the Communist conspiracy," Leith said, adding that Bernays spread the rumour among his contacts in the media to enflame public opinion against Guatemalan President Jacobo Arbenz, the country's democratically elected leader.

"(The press) claimed that he was a Communist leader and that was dangerous to the security of the United States, and so they invaded and took the bananas," Leith said.

Arbenz had been trying to reform Guatemala's banana farming industry to make the food more available to his citizens, but the U.S. invasion destabilized the country and left it open to United Fruit (later renamed Chiquita Banana).

Leith says Bernays was successful in pushing the U.S. to invade Guatemala because he recognized that humans often let instinct drive their decisions, instead of listening to logic. He said Bernays learned to provoke people's xenophobia based on the theories of Freud, who suggested people are nothing more than evolved primates who retain their base animal instincts.

"Xenophobia, the fear of the other, which gets exploited by (Adolph) Hitler, gets exploited by lots of leaders, and now of course (Donald) Trump, is based on the idea that we are instinctually parts of groups and we fear the others," Leith said. "It's based on instinct, not emotion."

Joseph Goebbels, Hitler's Minister of Propaganda, was among the many admirers of Bernays's work, and employed many of his tactics when the Nazis were in power in Germany.

Leith said Bernays was a master at manipulating both instinct and emotion, pushing such behaviours as compulsive shopping to achieve status, and encouraging fear wherever possible to drive sales.

"We are governed, our minds are molded, our tastes are formed, our ideas suggested, largely by men we have never heard of," Bernays wrote in his book, "Propaganda." He said there are a "relatively small number" of individuals who influence social conduct and ethics, because they "understand the mental processes and social patterns of the masses.

"It is they who pull the wires which control the public mind."