Mensa recently inducted it's all time youngest member. Emmelyn Roettger Mensa's now youngest member joined at the age of 2. Mensa (the international genius society) only allows those who score in  the top 2% on one of 200 accepted standardized tests. As a baby her doctor's thought she was autistic because she didn't respond to toys or other things like a normal baby. On a hunch her mom brought her in to have her vision tested. It turned out she just needed glasses and from then on has been acting just like a baby with an IQ of 135 should be. She could already read at age 2 and recognize letters.