A person who has loving, caring and attentive parents may do better later on in life as he/she has been raised in a secure, casing manner. If the parents were careless and irresponsible, the child may not be that successful, because he/she will feel incompetent, and is more likely to do worse. Part of this is a self-fulfilling prophecy- if one doesn't believe in his self worth, he will never fulfill his potential.
While this is true, it could be said that a child with too much care and and attention will react negatively and instead be unproductive and lazy expecting others to attend to all their needs. I guess one could say it is also important to consider the personality of the child.