The Monkey In Your Wallet
You have done something stupid with money at some point. Recently, probably. Maybe even this week.
Here is the good news. It was never really you. You see, scientists at Yale taught monkeys to use money, actual coins, actual trades, actual purchases, and the monkeys immediately started making the exact same questionable financial decisions you did. Panic selling. Refusing to cut their losses. Losing their minds with jealousy over what the monkey next door got instead. One of them even started stealing....
The Monkey in Your Wallet is the book that explains why, using genuine, peer-reviewed research into primate psychology to show that most of your worst money habits aren't a personal failing. They're ancient, evolved wiring, tested and proven in animals who've never seen a bank statement, a mortgage, or a credit card statement in their lives.
Inside, you'll discover:
- The real, evolutionary reason a loss hurts roughly twice as much as an equivalent gain feels good, and why that single fact quietly runs more of your financial life than logic ever will
- Why your brain treats your future self, the one who'll actually retire, like a complete stranger you have no real obligation to help
- The genuinely funny, genuinely proven experiment where monkeys were taught to use money, and immediately began making the exact same mistakes you do
- Which of your financial instincts are hundreds of thousands of years old, and which ones, surprisingly, are entirely modern inventions with no evolutionary excuse at all
- How an entire industry has learned to speak your instincts' language fluently, without a single person behind the counter needing to be a villain
- Why understanding your own wiring is the first real step toward outsmarting it, and the small, boring systems that do the rest
Written by someone who spent twenty-five years inside financial services, watching how real people actually behave with money at scale, not in theory, not in a lab, but across millions of genuine decisions, this book finally answers the question underneath almost every bad financial decision you've ever made. Not what should I have done. Why did it feel so right at the time.
This book is for you if:
- You've ever wondered why you know the sensible choice and do the opposite anyway
- You love the kind of book that explains human behaviour through a slightly unexpected, thoroughly researched lens
- You want to actually understand your own financial instincts, not just be told to have more willpower
- You'd rather laugh at a monkey stealing tokens from a research tray than read another lecture about budgeting
You won't stop being a monkey by the last page. Nobody manages that. But you will learn to recognise him in you, the moment he reaches for your wallet, and be able to build the systems that keep him from winning.

