The pursuit of truth has preoccupied humanity since the beginning of time — scientists devote themselves to it, so too do historians and detectives, and professional poker players and police interrogators pride themselves on being able to quickly sniff out a "tell" or a lie. But the truth is, they're no better at it than anyone else.

All of us are easily deceived, including the so-called specialists, says author Malcolm Gladwell.

"There is zero evidence that this is a reliable indicator of lying," he says, purposely looking away, avoiding eye contact and fidgeting nervously with his hands.

"And yet, I can show you study after study of surveyed cops in every corner of the world, and they all think that's lying."

Gladwell starts looking away again, adding: "This is not lying. I am not lying right now. I'm just averting my eyes!"

It is that inability to accurately read people and decipher when they're actually telling the truth that drives Malcolm Gladwell's latest book, Talking To Strangers.

He begins it by asking, "Why can't we tell when the stranger in front of us is lying to our face?" Then he gets right into the case of Sandra Bland , who was pulled over by a police officer in Waller County, Texas, and was found dead in her prison cell three days later.

The authorities said she hanged herself in the cell after her arrest for allegedly kicking an officer following a traffic stop, but her family and others questioned the official version of events.

Malcolm Gladwell explains why he became obsessed with figuring out why Sandra Bland died in police custody. 0:43

In the days following Sandra Bland's death, Gladwell became obsessed with figuring out why so many incidents between police officers and black Americans go so horribly wrong.

"I thought it was powerfully characteristic of the moment we're living in," Gladwell says.

"You know, we're shouting at each other and we're misunderstanding what the other party is saying. And the story of Sandra Bland is part of a larger story of the consequences of the deliberate practice of turning police officers into paranoid skeptics of everyday life."

In his book, Gladwell proclaims that the death of Sandra Bland, "is what happens when a society does not know how to talk to strangers."

Matched vs. mismatched people

With a methodical, forensic-like approach, Gladwell explores his thesis through a wide range of true crime cases:

Bernie Madoff, who became one of the most notorious con artists of our time.

Jerry Sandusky, the retired college football coach who was convicted of rape and sexual abuse of children and who, like Madoff, got away with it for years before being exposed.

Amanda Knox, an American exchange student who spent almost four years in an Italian prison after being wrongfully convicted of murder because everyone, from the police interrogators to the prosecutors to the jurors, thought that Knox was guilty simply because she didn't behave like someone who was innocent.

Gladwell says Amanda Knox is a perfect example of someone who is mismatched — the kind of person we tend to get wrong when we try to deduce their thoughts based on their behaviour.

"People who are 'matched' are people whose internal emotions are expressed accurately and predictably on their face and in their body language," Gladwell explains.

"If they're happy they smile, if they're nervous they look away, and if they're sad they frown. But there are a large portion of people who, for wholly innocent reasons, just don't display their emotions in that way."

Malcolm Gladwell tells CBC's Andrew Chang that his research indicates that a surprising number of people are what he terms 'mismatched.' In other words, their physical behaviour doesn't necessarily corresponded with the typical reactions many people would assume they'd display when experiencing specific feelings and emotions. (Evan Mitsui/CBC)

In the book, Gladwell tells a personal story of how his father scared away an armed thief one night while on vacation.

"My father hears my mother scream and comes running out of the shower, and sees a large man with a knife to my mother's throat," says Gladwell.

"And my father, who was naked and 75 years old at the time, points to the guy and screams 'Get out now!' The 20-year-old guy runs away. My father was easy to misread because he would never show you fear on his face, despite the presence of fear in his heart."

Gladwell says he discovered in his research that a surprising number of people are mismatched like his father and Amanda Knox. And he says this can create enormous problems for the rest of us, because we look at them and we think we know what's going on inside their heads — but we really don't.

How well do we know Donald Trump?

Surprisingly, in a book that examines so many big names that have made headlines, Donald Trump doesn't get a single mention in Talking To Strangers.

So what's Gladwell's take on the U.S. president? Is he who he appears to be? Here are Gladwell's thoughts:

Malcolm Gladwell's latest book is about how people often misinterpret what others are thinking, based on their expressions and behaviour. This is what Gladwell says about whether the general public really understands Donald Trump. 0:45

Future of social media

Considering the amount of time that Donald Trump spends on Twitter making his thoughts public, Gladwell says the U.S. president is certainly not a stranger to most of us. And like Trump, social media is another topic that you won't find in Talking To Strangers.

It might seem a strange exclusion for a book that's entirely about misunderstanding others, but it doesn't mean Gladwell doesn't have a take on how social media affects us.

Gladwell says he's on Twitter, but has never taken it seriously, for example. He also considers the emergence of podcasting a sign that people are growing tired of social media.

"What is podcasting? It's the antithesis of Twitter. It's people who are now willing to sit down and listen to an hour-and-a-half, in-depth interview. That's what's drawing them in and engaging them," says Gladwell.

"The notion that we would be organizing our life around a 140 character Twitter post is increasingly looking like a brief blip. People want engagement."

When asked about the staying power of social media, Gladwell says he's not convinced its pervasiveness will last much longer:

Malcolm Gladwell discusses the inevitable death of social media, with some very specific thoughts about where Twitter in particular is headed. 0:45

Next U.S. president

Gladwell is convinced that the next U.S. president won't be Donald Trump, and won't be active on social media.

"I honestly think that the way in which the current president has used and abused that medium is doing more to discredit it as a form of communication than anything else," says Gladwell.

"The next president of the United States, I'm convinced she will not tweet."

Gladwell offers a wide, almost Cheshire Cat-like smile when he says the word "she." So naturally, after he so willingly opened the door for a follow-up question, we asked who he thought would be occupying the White House after the 2020 U.S. election:

Despite America’s reluctance to vote for Hilary Clinton in the last U.S. election, Malcolm Gladwell predicts a female candidate will be elected to the White House in 2020. Here's why. 0:49

Advice for Canadian voters

Back to the premise for his latest book, whether he's talking about politicians or breaking down the psyche of notorious con artists, it isn't exactly new. In fact, a quote that springs to mind after reading Talking To Strangers isn't one of Gladwell's, but a line that entered pop culture in the early '70s:

"Smiling faces sometimes pretend to be your friend, smiling faces show no traces of the evil that lurks within. Can you dig it?"

Written by Norman Whitfield and Barrett Strong for Motown artists The Temptations and The Undisputed Truth in 1971, the Motown classic could indeed be part of the soundtrack of Gladwell's Talking To Strangers if it was ever considered for the screen. But what of those smiling faces seen on the campaign trail here in Canada over the past few weeks?

Many Canadians have already formed strong opinions about the candidates ahead of Monday's federal election, but are they warranted?

Host Patrice Roy from Radio-Canada, centre, introduces Federal party leaders, left to right, NDP leader Jagmeet Singh, Green Party leader Elizabeth May, People's Party of Canada leader Maxime Bernier, Liberal leader Justin Trudeau, Conservative leader Andrew Scheer, and Bloc Quebecois leader Yves-Francois Blanchet, before the Federal leaders French language debate on Oct. 10. (Sean Kilpatrick/Pool via Reuters)

Gladwell says democracy would be better off if voters couldn't see the party leaders and didn't form personal assessments about their character.

His advice to Canadians voting in the federal election is to put aside any preconceived notions of who they think the candidates are.

"Because you don't know them. And because that can only mislead you," he says.

"In fact, in my perfect world we would never meet or personally see the people running for office. We would only hear them. We would hear what they have to say about their view of society, what they think the problems are and how they intend to fix those problems. That's what matters," says Gladwell.

"Wouldn't we be better off if we didn't know whether they were male and didn't know how old they were? Where we're forced to judge them on what they actually believe? So, I mean, it'll never happen, but what if you were just told it's A, B, C, D, E and F. Here's what they believe in. Make your choice?"

WATCH | The National's interview with author Malcolm Gladwell: