What makes a winner? Why do some succeed both in life and in business, and others fail? The 'winner effect' is a term used in biology to describe how an animal that has won a few fights against weak opponents is much more likely to win later bouts against stronger contenders. As Ian Robertson reveals, it applies to humans, too. Success changes the chemistry of the brain, making you more focused, smarter, more confident and more aggressive. And the more you win, the more you will go on to win. But the downside is that winning can become physically addictive. By understanding what the mental and physical changes are that take place in the brain of a 'winner', how they happen, and why they affect some people more than others, Robertson explains what makes a winner or a loser - and how we can use the answers to these questions to understand better the behaviour of our business colleagues, employees, family and friends.