What an interesting statement! I have never heard it before, and now I will be paying better attention to see if it's true!
Thank you, ladies, for your comments. This quote was one that I found interesting, too. It took me a while to fathom it, but I think that it's true when applied to those who are capable of laughter: we can, of course, truly love those who are physically or mentally incapable of it whether because of age or defect. Still, once the age of reason has been reached, the deepest loves involve those with whom we can truly be ourselves, and with whom laughter bubbles up like a merry spring. At least it has been that way in my experience.