“That Girl” actress Marlo Thomas, 82, and talk-show host Phil Donahue, 84, spent months interviewing celebrity couples for their new book, What Makes a Marriage Last: 40 Celebrated Couples Share with Us the Secrets to a Happy Life.

The work includes marriage tips from couples like Kevin Bacon and Kyra Sedgwick, as well as Viola Davis and Julius Tennon.

Appearing in the latest AARP the magazine, Thomas and Donahue explained: “As different as these couples’ stories are, they share a common plotline: that of two people joining hands and stepping up to the most challenging, invigorating, inspiring, infuriating, thrilling, terrifying, delightful and heavenly job on Earth — making a marriage last.”

The pair, who met when Thomas was a guest on Donahue’s talk show in 1977, revealed that the key to their own success as husband and wife has been strong communication.

“Through the years you learn that everything is not that big a deal, and this isn’t going to break us up no matter what, so you get used to saying, ‘OK, let’s just talk it out,’” said Thomas.

Donahue joked: “The secret of good communication? Screaming helps! At least then you know if whether the person you’re screaming at is listening. Then go in the other room and count to 10.”

He added, “A little humour certainly in a marriage goes a long way.”

Click to View Gallery
Celebrity Couples Who’ve Made It Past The 20-Year Mark