BEHIND THE MASK

During a recent visit to Buenos Aires from Los Angeles, my friend Nancy told me about an interview she once read with Robert Redford in which he explained how he came to cast America's one-time sweetheart Mary Tyler Moore as the ice-queen bitch mother from hell in his Oscar-winning 1980 film, Ordinary People. As he told it, he was sitting on the beach, when in the distance he noticed Mary Tyler Moore walking by. She looked nothing like the sweet-as-pie Mary Richards that her fans had come to know and love during her years on her eponymous TV show. Instead, she was wearing a brittle, frosty expression on her face, like a steely warning to anyone who might consider interrupting her deep contemplation. Robert Redford had an epiphany: This seemingly sweet as apple pie actress had a dark side, and she could do justice to the role. His female lead was as good as cast.

Listening to this story, I began to think of one of my favorite quotes, from Maya Angelou. The first time I heard it, many years ago, Oprah Winfrey was repeating it on her talk show: "When people show you how they are, believe them." The idea is simple enough -- if not drop-dead obvious -- but what an effective way of expressing it. I'd come to a similar conclusion years earlier, in middle school, when I realized that the best way to discover a person's true colors is to look at them when they don't realize that anyone is looking.

The first time I tested this theory was when I was in seventh grade, and my sister's college boyfriend, Eric, came to visit. The entire family loved him. He was handsome, charming, and most of all, he professed to be God-fearing. But during this visit, he showed me how he was -- and I believed him. I walked into the bedroom where he was crashing, and before he noticed I had entered the room, I caught the strangest look on his face. It was steely and calculating, almost scary in its intensity and the complete antithesis of the blank, guileless mask he had been wearing in front of the family. I knew then and there that Mr. Right was all wrong, and as it turned out, I was right.

So was Robert Redford. No one will ever know for sure what was really going on behind that smile that MTM used to turn the world on during the '60s and '70s, but if you're going to tap into your dark side, you might as well wow the critics (see the video below to find out why) and score a best actress Oscar nomination in the process.

MORE MONSTROUS MOVIE MOMS

• Gladys Cooper as Mrs. Windle Vale in Now, Voyager
• Gladys Cooper as Mrs. Railton-Bell in Separate Tables
• Angela Lansbury as Eleanor Iselin in The Manchurian Candidate
• Faye Dunaway as Joan Crawford in Mommie Dearest
• Angelica Huston as Lilly Dillon in The Grifters
• Oprah Winfrey as Sethe in Beloved
• Julianne Moore as Laura Brown in The Hours
• Debra Winger as Abby in Rachel Getting Married
• Kate Winslet as April Wheeler in Revolutionary Road