...to my knowledge there's been very little success in finding any early childhood characteristics that have a strong positive correlation to adult success...
Of course, one of the really interesting conclusions of that study was that children can improve their capacity for delayed gratification through practice.
The Stanford Marshmallow study is one that springs to mind - delayed gratification in children correlates strongly with adult success: http://www.sybervision.com/Discipline/marshmallow.htm
Of course, one of the really interesting conclusions of that study was that children can improve their capacity for delayed gratification through practice.