Robert had spina bifida, which might be related to the fact that his parents were first cousins. Not sure how to draw that into the tree, though.
 
He died in his early twenties.
 
My Grandma always felt he was excessively wrapped in cottonwool, and not allowed to play like an ordinary child. My father's memories are that when all his cousins were together, Robert was frequently the one who was missing.