I would say that the surest measure of a man's or a woman's maturity is the harmony, style, joy, and dignity he creates in his marriage, and the pleasure and inspiration he provides for his spouse.
Source: In Older & Wiser, ed. by G. B. Dianda and B. J. Hofmayer, 1995.
-- Benjamin Spock, (May 2 1903-1998), US physician, author; He was a major influence on modern U.S. child-rearing practices; Common Sense Book of Baby and Child Care, 1946 has sold millions of copies.