Ask a numerology book which number is the intelligent one and you'll almost always get 7. That's not because anyone has tested it — it's because 7 was assigned keywords like "analytical," "introspective," and "seeker of truth" decades ago, and those words happen to overlap heavily with how we culturally describe intelligence.
It's worth noticing the circularity: 7 sounds smart because it was written to sound smart, not because people with a calculated 7 test higher on anything.
