Success in investing doesn't correlate with I.Q. once you're above the level of 25. Once you have ordinary intelligence, what you need is the temperament to control the urges that get other people into trouble in investing.
In the first season of the television series Seinfeld there is an episode called "The Stock Tip." It opens with George Costanza excited about a stock. He received a tip from an insider that the stock was about to rocket, and he made a proposition to Jerry.
George enthusiastically explained that his friend "Wilkinson" had inside information about a small company that was about to go through a "big merger." George's friend "wasn't even supposed to say anything." If George bought shares on this tip, Wilkinson would tell him the exact time to sell.
"What does the company do?" Jerry asks.
"It's called Centrax. . . . they've got some new type of technique for televising opera . . . some sort of electronic thingy," George explains.
They invest, but the stock doesn't go up as expected. In fact, the stock declines, day after day. Finally, after losing almost half his investment in a few days, Jerry can't tolerate the pain any more, declaring, "I don't want to think about this. I'm selling!"
George gamely replies, "I'm keeping it. I'm going down with the ship!"
A week after selling, Jerry looks up Centrax's stock quote in the newspaper. The stock is up considerably from where he had bought it. His ...