Find out what is the meaning of the quote: “Big jobs usually go to the men who prove their ability to outgrow small ones.”
The word “prove” means to show that it is true or show beyond doubt.
The word “ability” means physical or mental power or skill.
The word “outgrow” means to leave behind as one matures or improves. Or simply means surpass.
As for this quote “Big jobs usually go to the men who prove their ability to outgrow small ones.”, it means people who can show convincingly that they have the capability to handle their present and lower-rank job very well.
Their ability or skill have surpassed their present job requirement. So it is time to give them to handle a bigger job scope.
In other words, now they are ready to manage a much heavier and important job responsibility.
According to Wikiquote, this line probably NOT by Theodore Roosevelt.
It is marked as “Unsourced“.
But in the book “Mansfield’s Book of Manly Men: An Utterly Invigorating Guide to Being Your Most Masculine Self” by Stephen Mansfield, this line is said to be by Theodore Roosevelt on page 28.
It mentioned that this line is quoted in The Management Review, Vol.6. American Management Association (1919).
Note: Personally I’m still unsure about the authenticity source of this quote.
So the attribution of this quotation as published here, I leave it as “Unknown“.
*Here is list of verified ability quotes with full citations that linked to the original or reliable sources.