(Most of these charts have been pulled from Intelligence: All that Matters. Here are nine facts that help explain IQ and why it matters. And the truth is some people start ahead. In a new book, Intelligence: All that Matters, Ritchie persuasively argues that IQ doesn't necessarily set the limit for what we can do, but it does give us a starting point. (Richie and I go further into why IQ research makes some people uncomfortable in a Q&A here.) And psychologists have been able to replicate these findings over and over.

But according to Stuart Ritchie, an intelligence researcher at the University of Edinburgh, there's a massive amount of data showing that it's one of the best predictors of someone's longevity, health, and prosperity. IQ is often dismissed as antiquated, misguided, or less important than personality traits. But there is one number that probably says a lot about you, whether you know it or not: your IQ, or intelligence quotient. (President Donald Trump recently bragged to Forbes that he would 'win' if his IQ test score was compared to that of his Secretary of State, Rex Tillerson.)