Being an early reader. British researchers surveyed 2,000 pairs of identical twins. And despite having the same genetics, whichever twin that started reading earlier wound up the higher IQ score. Did they read earlier because they were smart? No—the scientists determined that learning to read earlier actually helped their brain develop faster.
Having other mental health concerns. Unfortunately, being a genius may also been a predisposition to having a serious mental health issue. A study of Swedish teenagers found that the smartest kids were four times as likely to have or one day develop bipolar disorder.