For years, Daemon Fairless would swell with pride whenever he told the story about the time he headbutted a man in the face on the subway.
It was New Year's Eve in Toronto, and the man was drunk, belligerent and making a scene, Fairless said.
"The long and short of it is I got up, told him to sit down and after he threatened my wife, I smashed his nose with my forehead," he said.
"The police came, he was arrested and I was the quote-unquote good guy in that situation."
But the truth, Fairless said, is much more complicated.
"The whole time, building up in me was this kind of icy rage. I kind of stopped thinking of him as human and started thinking of him as an object to punch," he said.
"I just cocked my head back and brought it down on his face — and then things were a blur."
Disturbed and confused by his own anger and bloodlust, Fairless — a former As It Happens producer — set out to explore the roots of male violence in his new book Mad Blood Stirring: The Inner Lives of Violent Men.
"I'm, 99.9 per cent of the time, a really, I think, even-keeled, gentle, friendly, gregarious person. And then that tiny little percentage of the time, I would find my anger overwhelming," Fairless told As It Happens host Carol Off.
"I was raised by people who were really anti-violence, anti-macho ... so I was trying to understand what was going on inside of me."
For his book, Fairless talked to some of Canada's most violent men.
One central figure is Darrell (not his real name), a serial sexual predator incarcerated in a maximum-security Canadian prison.
Darrell started attacking women when he was a teenager.
"He lost his own virginity raping, which I had trouble getting my head around," Fairless said.
"And then, weirdly, he'd do things after he did this. He'd apologize. He was the most Jekyll and Hyde person in some ways."
In fact, the first time a woman reported him for sexual assault in the Greater Toronto Area, the police let Darrell go, Fairless said.
"He was so polite, so disarming and so sweet, if I can use that word, that the cops just didn't think he was the kind of guy to worry about," he said.
"That's how he presented to the world and I think, weirdly, that's how he presented to himself as well. That's how he thought of himself with the exception of this kind of monster that was inside of him."
Understanding the disconnect between perception and behaviour is key to understanding male violence, Fairless said.
In a 2015 University of North Dakota survey of 86 men, 31.7 per cent said they would act on "intentions to force a woman to sexual intercourse" if they could get away with it.
But when asked the same question phrased differently, only 13.6 per cent said they would "rape a woman."
Studies like that, Fairless said, show that men have a disturbing capacity to delude themselves about their own behaviour.
"There's this huge ability for guys to justify the violence they're doing," he said.
"We hear the women with the Me Too movement right now, talking over and over about there's all these ways that guys have of shutting down and diminishing, rationalizing not just sexual violence, but you know, sexual harassment."
The same goes for other forms of violence, he said.
"I think I can go back to every single fight I've gotten into — I haven't been in tons, but say a dozen or so — I can go back and absolutely objectively say that there was no need to interfere violently in any of those cases," he said.
"I could have just stayed out and things would have been fine. I was escalating already volatile situations ... but in the moment, subjectively, I wasn't aware that's what I was doing."
Fairless also interviewed a man he calls The Killer — a Canadian man who raped and murdered several young women.
Unlike Darrell, The Killer seemed to have no remorse for his actions, and no capacity for empathy at all.
"I think we have this tendency to want to try to categorize people like him as 'others' — as not quite human," Fairless said. "That's a little precious of us."
Most violence, he said, is committed not by monsters and freaks — but by regular, everyday, run-of-the-mill men.
"All the terrible stories about Syria and Rwanda and Yugoslavia, genocides, that level of thing — what happens is they might be led by a psychopath or a sociopath, but the people doing the genocide, the people killing wholesale slaughter, are average people," he said.
He doesn't see his prose about The Killer as "a portrait of an aberrant monster," he said, but rather as "a self-reflexive exercise — because we have this capacity, and we have to own up to that."
Fairless said he believes the key to moving forward is for men to confront their inner demons and unpack their darkest desires.
"I'm a different person after writing this book. I am not the same guy who's going to get into fights — precisely because I looked inside in a very unpleasant way. I mean, it really tore me apart to write this book," he said.
"I talk a lot about some of the deep roots of these emotions. That doesn't mean the behaviour is pre-determined. That's just not true at all."
Mad Blood Stirring from Penguin Random House Canada hits shelves Tuesday.
Story written by Sheena Goodyear. Interview produced by Julian Uzielli. Video by Mallika Viegas with animations from Ben Shannon.
Correction: An earlier version of this story said a woman reported Darrell for sexual assault in Montreal. However, it actually happened within the Greater Toronto Area.