You may be a successful investor. You may not be. But if you have read anything written about our investing brains in recent decades, you will know that they are full of tripwires, defects and bugs.
Without a doubt, this description beats the one that preceded it. Until the mid-20th century, our membership of the species homo economicus – the embodiment of the neoclassical economics paradigm – ensured that our decisions were always rational, controlled and utilitarian.
Only they weren’t. Of course they weren’t. Investors have always suffered from overconfidence, a tendency to overvalue what they already own, chronic aversion to losses, and an inability to separate skill from luck. We may think we know what rational behaviour is. But it is forever outside our grasp.