The bell curve distribution for IQ scores tells us that two thirds of the world’s population has an IQ somewhere between 85 and 115. This means that some four and a half billion people around the globe share just 31 numerical values (“he’s a 94,” “you’re a 110,” “I’m a 103”), equivalent to 150 million people worldwide sharing the same IQ score. This sounds a lot to me like astrology, which lumps everyone into one of 12 signs of the zodiac.