Comes from David Brook's column:
"Her father died when she was 9, leaving one such gap. (It is amazing how many people who suffer parental loss between the ages of 9 and 13 go on to become astounding high achievers.)."
The only reason he thinks this is amazing is his prejudiced belief that only persons from intact nuclear families can succeed. Also, this is another example of how books makes assertions without backing them up with any empirical evidence. We don't care what your individual experience tells you. There are facts to be had about this kind of thing!