Common mistakes in careers advice: when should you trust sayings?

“Look after the pennies, and the pounds will look after themselves.”

Often in careers advice, as in life generally, you will be handed some proverb. But sometimes these sayings aren’t true, how can you know when to trust them? A common mistake in career choice is to blindly accept common ideas like this without good reason.

You can’t always rely on hard studies being available, you have to rely on your intuitions a lot of the time. One way of using your intuition better that I’ve found effective is to follow this plan:

  • Reverse the principle and see if the opposite idea makes sense
  • Tell two stories, one to explain the principle, one to explain the reverse.
  • Use these stories to find out when to trust the principle.

But first, is there a real problem here to solve?

Why isn’t normal intuition enough?

Your intuitions can convince you that ideas are believable even when they are false, or even contradicted by other beliefs. It’s important to know how (un)trustworthy your intuitions are. A typical person’s instincts about social situations are excellent. A typical person’s instincts about nuclear physics are terrible. For an autistic nuclear scientist the reverse might be true. In general, without a lot of experience involving regular feedback intuitions tend not to be reliable.

But, even when you have good feedback, there is a special bias involved in common expressions that needs to be dealt with consciously.

The most common way our intuitions assess new ideas is by “trying them on”: trying out believing them and seeing how easy it is. If the idea is very easy to process then it will seem more likely to be true.

This means our intuitions are biased by the way ideas are presented. It should be obvious that the fact something rhymes doesn’t make it true, but people are actually more likely to agree with a statement if it rhymes.1

This bias can be dealt with by some techniques I’ll outline below.

Why does thinking about the opposite help

Law courts have two sides for a reason: finding one unbiased person is a lot harder than finding two people with opposite biases. You can deal with your own bias the same way. If you want to know whether to believe an aphorism or not, “try on” believing the opposite principle. But this isn’t always as easy as you might expect:

Quickly! Think of anyone from Asia other than Genghis Khan.

If you’re like most people you will have spent most of your thinking time coming up with more and more information about Genghis Khan. Your intuitions are bad at understanding the idea of “not”. It’s easier to believe things said as positive statements. So when reversing a principle , don’t simply put “not” at the start. Turn it into a positive statement.

Take our example at the start: “look after the pennies, and the pounds will look after themselves.” Try to reverse it by saying “Don’t look after the pennies, the pounds won’t look after themselves”. Does that sound believable? Of course not. But how about “haggle more over the price of the house than the price of the wallpaper”? Does that sound believable? Yes. But now we have two statements, which mean exactly opposite things, both of which seem intuitively believable.

The fact that how much we believe something depends so much on irrelevant factors like how it is phrased should make us worry about how much we trust sayings. We shouldn’t trust “look after the pennies” now that we’ve found a saying that’s believable but which means the opposite. How should we decide which of these sayings to trust?

Explain it with a story

Alice went to a restaurant and ordered a steak. When it arrived it was crawling with maggots. Alice walked out of the restaurant.

Did Alice pay for the steak? You know that she didn’t: but nowhere in the story are you actually told that. Stories contain a huge amount of implicit information. Often by telling a story to explain something you can make inferences you wouldn’t have been able to before.

“The best managers leave their office doors open”. If you think only about the principle you will leave your door open and do nothing else. But see how much more we can do with an explanation: “The best managers leave their office doors open, because the constant stream of people who come in and talk to them provides lots of new ideas, this makes them far more creative and so better”. With the story you can see that a policy of eating lunch with a new person every day would do the same thing.

Test it with a story

Remember the first point, our intuition tends to agree with things. With a story this is even more true. It is very important to also tell the story of the reversed principle. You can learn from this when a principle is justified. Take the manager example again:

“The best managers keep their doors shut, because that way the have very long uninterrupted stretches. Understanding a very complex strategy is like building a house of cards in your head. It’s only after a long time remembering all the connections that you can make progress. So the long stretches are far more valuable than the the same amount of time in small chunks.”

This second story also makes a lot of sense. But it cannot be that both the principle and its opposite are true. If you have two stories that say opposite things they must rely on different assumptions. If you find these assumptions then you can work out when to trust the principle.

In the case of the manager we can see from these two stories that each approach is best only when working on certain kinds of job. Specifically we can predict that a closed door will help when the manager needs to deal with a large and complex strategy problem. We can likewise predict that the open door approach will work when the problem is how to create a novel solution for relatively simple problems.


Many careers advice and charity sites have helpful advice in intuitively appealing sayings. You should be careful in how you process this advice.

Try and apply the above method to these common ideas, do they actually make intuitive sense.

  • It’s better to send one personal letter than a dozen form letters.
  • Do what you love.
  • Think globally, act locally.
  • Think about your values, not your skills.


  1. McGlone, M. S.; J. Tofighbakhsh (2000). “Birds of a feather flock conjointly (?): rhyme as reason in aphorisms.“. Psychological Science 11 (5): 424–428.