Some heuristics are useful but fragile.
For example, "trust doctors". In most cases, this is a very useful heuristic—a mental shortcut you can rely on without needing to think too hard about it. Doctors have years of training, access to the latest medical research, and a wealth of experience. When you're sick, following their advice is generally a good idea.
But heuristics can break down spectacularly when contexts shift. Only about 80 years ago, there was a solid window of time where it was not just acceptable but highly recommended to lobotomise people who seemed depressed or irritable. Imagine walking into a doctor's office feeling a bit down, only to walk out with part of your frontal lobe surgically removed. Zoloft used to be a zap to the brain or an ice pick in your skull.
This isn't ancient history either. In the 1950s and 60s, doctors routinely prescribed cigarettes for weight loss and stress relief. In the 90s, they over-prescribed opioids, kickstarting an addiction crisis we're still grappling with today.
Heuristics are useful, but equally useful are the ability to consider things from first principles, the habit of testing assumptions, and a willingness to dig for data. When faced with important decisions, it's worth taking a step back and asking: "Does this heuristic still apply in this situation?"
Take the common advice to "follow your passion". It sounds great on the surface—who doesn't want to be passionate about their work? But blindly following this heuristic can lead to frustration and career dead-ends. Instead, consider the principles behind it: engagement, skill development, and market demand. You might find that cultivating passion through mastery is more effective than chasing an elusive "dream job".
Or consider the investment heuristic "buy low, sell high". Simple, right? But in practice, it's incredibly difficult to time the market consistently. A more robust approach might involve regular, disciplined investing based on your risk tolerance and financial goals.
The key is to use heuristics as starting points, not ending points. They're shortcuts, not substitutes for critical thinking. When the stakes are high, don't be afraid to challenge conventional wisdom. Dig into the data, seek out diverse perspectives, and be willing to update your beliefs.
