Or maybe it is you.
Five to 10 per cent of the population qualify as psychopathic, according to David Gillespie, author of Taming Toxic People: The Science of Identifying and Dealing With Psychopaths At Work and At Home.
A study last year found the rate could be as high as 20 per cent among corporate leaders.
Your average psychopath will display a number of traits: a grandiose sense of self-worth, lack of remorse or guilt, shallow emotional intelligence and little empathy, among others.
"There is usually a dichotomy between how they appeared when you first met them, and how they subsequently appear," Gillespie told Lateline.
"When you first meet them they are incredibly charming. They tell you everything you want to hear and seem like the most genial and wonderful people you've met in your life.
"Very shortly after they are different. People often describe it as a Jekyll and Hyde nature where they're fine when they are ingratiating themselves with you, and suddenly they're plain nasty or dismissive towards you."
What it drilled down to, Gillespie said, was someone who had no empathy for others.
"I am not for a minute suggesting they are a serial killer or any other kind of criminal," he writes in the book.
In fact, he said, criminal psychopaths — the kind you see of true crime TV shows — were low-functioning psychopaths, "the ones without the resources to achieve power and money and fame".
"The more high-functioning psychopaths achieve all of those things without ever committing an overt criminal act."
That includes politicians, Gillespie said.
"The fact modern politicians score high on psychopathic scales shouldn't come as a surprise to anybody," he said.
"The thing that drives psychopaths is absolute power over people. It's the perfect job as far as a psychopath is concerned."
I definitely have one in my life, so what can I do?
There is no evidence you can change a psychopath, Gillespie said, so do not waste your time trying.
"What you can do is control them ... with honesty, transparency, and structured decision-making."
His number one tip for dealing with the psychopath in your life? Look after yourself.
"Their primary motivation is to extract loyalty and resources from you, and servitude," he said.
"If you are going to survive that, whether it's at work or at home, then you have to provide a support network for yourself.
"That means don't let them cut you off from your friends and family ... you will need them constantly when you are dealing with the confusion and disorientation that [the psychopath] brings to your life."
Gillespie likened a psychopath to a piece of enriched uranium.
"Ignoring it or handling it badly can have horrific consequences," he writes in the book. "But if you are careful and design the system containing it well, it can produce enormous benefits."
Key traits of a psychopath
- Fluent liar
- Emotionally manipulative
- Completely lacking in remorse or guilt
- Emotional shallowness and callousness
- No responsibility for their actions
- Highly controlling
- Aggressive and intimidating
Source: David Gillespie