Use Your Brain, Not Your Education

Pop Quiz

Solve these elementary school problems quickly in your head –

  1. A ruler and pencil cost a dollar and ten cents. The ruler costs a dollar more than the pencil. How much does the pencil cost?
  3. Your body has a rash. Each day the rash doubles in size. If it takes 12 days for the rash to cover your entire body, how long would it take the rash to cover half your body?

How did you do? You can check your answers below, but I’m guessing some of you confidently thought the ruler cost a dollar, and that pesky rash took 6 days to cover half the area.

But, why?

Because Studies show that educated adults still take mental shortcuts that skip rational thought and lead to a foolish decision. When people face an uncertain situation, they don’t carefully evaluate the information or look up relevant statistics. Instead, their decisions depend on a long list of mental bypasses. These shortcuts aren’t a faster way of doing the math; they’re a way of skipping the math altogether. Asked about the ruler and pencil, we forget our arithmetic lessons and instead default to the answer that requires the least mental effort.

Does your degree help or hurt?

This was revealed in a study in the Journal of Personality and Social Psychology, which also says that those with higher S.A.T. scores are much more susceptible to these thinking errors. Education is far from a saving grace, as more than fifty percent of those at Harvard, Princeton and M.I.T. that took the survey gave an incorrect answer to the pencil and ruler question.

So, what to do?

There’s really no easy answer, because the study also shows being self-aware of these mental shortcuts didn’t lead to overcoming them in any significant way. Subjects were still prone to overconfidence, predictive fallacy, and underestimation.

Be the tortoise, not the hare.

One tip universally acknowledged is to slow down. Slow the thinking process down a bit. Fast decisions are much more biased decisions, leading to those pesky shortcuts in logic. A measured, paced conclusion usually leads to better results.

The ruler costs $1.05, the pencil costs 5 cents.


The rash would take 11 days to cover half your body.

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