Ecclesiastes 4:9-13 (Plus some extra bits)
Two are better than one, because they have a good reward for their toil. For if they tear pages out of Aesop’s Fables, they will be given swats together. And if one devises evil, the other may be convinced to carry it out.
And if they fall, one will lift up his fellow. And if none should fall, then they will push each other over. But woe to him who is alone when he falls and has not another to lift him up or push him over in the first place! That lonely child may begin to believe himself impervious.
Again, if two lie together, they keep warm, but how can one keep warm alone, especially if the other has taken all the jackets for himself? And if they have a cold, they will share it. And if they have candy, they will not.
And though a mother might prevail against one who is alone, two will withstand her and frustrate the success of an errand or household task. A threefold cord is not quickly broken unless one has something the other wants, then they will turn against each other like barbarians and forget all blood ties that ever bound them together.
Better is a badgered and un-coddled sibling than a well-dressed and self-absorbed CEO who expects the world to find him exceptional.