Micael Dahlén, one of Sweden's most well known authors and out-of-the-box thinkers, has previously released books that led to heated debates and discussions. But the real shock, he saved for his latest book.

The 38-year-old professor at the Stockholm School of Economics travelled over three continents to meet and interview five of the world’s most famous murderers.

His new book “Monster” tells the horrifying stories of Charles Manson’s brutal slaughters that brought an end to the swinging sixties, Dorothea Puente’s bone-filled garden, Issei Sagawa’s cannibal feast in Paris, Wayne Lo’s violent school shooting and Peter Lundin who with his bare hands cracked his own mothers neck.

In an interview with The Swedish Wire, Micael Dahlén explains why TV and books are filled with sickening killings, why heartless mass-murderers drown in love letters and how it felt standing face-to-face with a Japanese cannibal.

What made you want to write a book about these "monsters"?
"What first got me going was an open letter that was published in the nation's major newspaper, it was written by a man who was incarcerated for killing two police officers, he was the nation's most infamous killer. The headline read: 'Please stop sending me love letters', and in the letter he pleaded for women to stop sending him all these love letters that flooded the prison post office.

"It really bugged me. And it got me thinking - how can a person do the worst imaginable thing on the human repertoire and be desired for it?And once I started thinking about it, I began seeing it everywhere - in newspapers and magazines, books, TV, movies, merchandise: Killers becoming icons, and virtual industries. It started a long process within me, which eventually made me conduct a lot of studies and experiments, travel around the world to meet some of the globe's most famous killers, and totally messed up my head, I couldn't stop, so I needed to write the book to finally move on.

You're a professor of economics and marketing; what's the connection to murderers and how will you use these insights in your research and teaching?
"Murder sells. Big. People like Charles Manson are multi-million dollar industries. You find him in movies, bands like Guns N Roses and Marilyn Manson have recorded his songs, every other week there's a TV documentary about him, there have been art exhibitions, there's t-shirts, posters and more. I wanted to understand just how big this thing is, and why and how that's possible. What does it say about us? My particular research field is social psychology, and this says quite a lot about the human psyche and what (whether we like it or not) attracts our attention.

"To be honest, I try to steer clear from applying it to marketing, it's too horrible. It was never my intention to learn for my "day job", this was just something I had to do for my own piece of mind.

Why are we all so fascinated by murders and murderers?
"The most fundamental explanation is that murder is the most horrible thing known to humanity, an act no one is allowed, and should not even be able to commit, an uncrossable boundary. Crossing this boundary sends a signal that the person is not like the rest of humanity, maybe not even human. And so we tend to perceive them as different from us and turn them into myths and storylike creatures. Also, coming close to a killer is like balancing on the fine line between life and death, it actually gives the same scary rush as, for example, bungy-jumping: coming close yet surviving.

"And a really scary thing I found in my experiments was that normal people have much darker thoughts and drives than we'd like to admit, but we don't act on them, killers give people a twisted chance to vent.

How did it feel to meet Japanese cannibal Issei Sagawa alone, face-to-face?
"It was one of the strangest experiences of my life. It took me so long to find him and to get to know him, during the course I doubted that he even existed, I began thinking that he was just an urban legend, so bizarre is his persona and the story behind him. But that was nothing compared to meeting him in person and hearing his own words. It made me really scared.


Quick Facts:

• Micael Dahlén, born 1973, is a author and professor of economics and teaches at the Center for Consumer Marketing at the Stockholm School of Economics, Sweden.

• Dahlén's most famous book Nextopia explores common denominators among such divergent areas of research as evolutionary biology, social psychology, epidemiology, economics and business administration.

• In 2008 Journal of Advertising ranked Micael Dahlén as number 10 in the world among researchers within the field of advertising